research on sunscreen

May 8, 2024

Why Aren ’ t Better Sunscreens Sold in the U.S.?

A decade after Congress told the FDA to expedite the approval of more effective sunscreens, the federal government still has not approved sunscreen ingredients that are safely being used around the world

By Michael Scaturro & KFF Health News

DBenitostock/Getty Images

When dermatologist Adewole “Ade” Adamson sees people spritzing sunscreen as if it’s cologne at the pool where he lives in Austin, Texas, he wants to intervene. “My wife says I shouldn’t,” he said, “even though most people rarely use enough sunscreen.”

At issue is not just whether people are using enough sunscreen, but what ingredients are in it.

The Food and Drug Administration’s ability to approve the chemical filters in sunscreens that are sold in countries such as Japan, South Korea, and France is hamstrung by a 1938 U.S. law that requires sunscreens to be tested on animals and classified as drugs, rather than as cosmetics as they are in much of the world. So Americans are not likely to get those better sunscreens — which block the ultraviolet rays that can cause skin cancer and lead to wrinkles — in time for this summer, or even the next.

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Sunscreen makers say that requirement is unfair because companies including BASF Corp. and L’Oréal , which make the newer sunscreen chemicals, submitted safety data on sunscreen chemicals to the European Union authorities some 20 years ago.

Steven Goldberg, a retired vice president of BASF, said companies are wary of the FDA process because of the cost and their fear that additional animal testing could ignite a consumer backlash in the European Union, which bans animal testing of cosmetics, including sunscreen. The companies are asking Congress to change the testing requirements before they take steps to enter the U.S. marketplace.

In a rare example of bipartisanship last summer, Sen. Mike Lee (R-Utah) thanked Rep. Alexandria Ocasio-Cortez (D-N.Y.) for urging the FDA to speed up approvals of new, more effective sunscreen ingredients. Now a bipartisan bill is pending in the House that would require the FDA to allow non-animal testing.

“It goes back to sunscreens being classified as over-the-counter drugs,” said Carl D’Ruiz, a senior manager at DSM-Firmenich, a Switzerland-based maker of sunscreen chemicals. “It’s really about giving the U.S. consumer something that the rest of the world has. People aren’t dying from using sunscreen. They’re dying from melanoma.”

Every hour, at least two people die of skin cancer in the United States. Skin cancer is the most common cancer in America, and 6.1 million adults are treated each year for basal cell and squamous cell carcinomas, according to the Centers for Disease Control and Prevention . The nation’s second-most-common cancer, breast cancer, is diagnosed about 300,000 times annually , though it is far more deadly.

Though skin cancer treatment success rates are excellent, 1 in 5 Americans will develop skin cancer by age 70. The disease costs the health care system $8.9 billion a year , according to CDC researchers. One study found that the annual cost of treating skin cancer in the United States more than doubled from 2002 to 2011, while the average annual cost for all other cancers increased by just 25%. And unlike many other cancers, most forms of skin cancer can largely be prevented — by using sunscreens and taking other precautions.

But a heavy dose of misinformation has permeated the sunscreen debate, and some people question the safety of sunscreens sold in the United States, which they deride as “chemical” sunscreens. These sunscreen opponents prefer “physical” or “mineral” sunscreens, such as zinc oxide, even though all sunscreen ingredients are chemicals.

“It’s an artificial categorization,” said E. Dennis Bashaw, a retired FDA official who ran the agency’s clinical pharmacology division that studies sunscreens.

Still, such concerns were partly fed by the FDA itself after it published a study that said some sunscreen ingredients had been found in trace amounts in human bloodstreams. When the FDA said in 2019 , and then again two years later , that older sunscreen ingredients needed to be studied more to see if they were safe, sunscreen opponents saw an opening, said Nadim Shaath , president of Alpha Research & Development, which imports chemicals used in cosmetics.

“That’s why we have extreme groups and people who aren’t well informed thinking that something penetrating the skin is the end of the world,” Shaath said. “Anything you put on your skin or eat is absorbed.”

Adamson, the Austin dermatologist, said some sunscreen ingredients have been used for 30 years without any population-level evidence that they have harmed anyone. “The issue for me isn’t the safety of the sunscreens we have,” he said. “It’s that some of the chemical sunscreens aren’t as broad spectrum as they could be, meaning they do not block UVA as well. This could be alleviated by the FDA allowing new ingredients.”

Ultraviolet radiation falls between X-rays and visible light on the electromagnetic spectrum. Most of the UV rays that people come in contact with are UVA rays that can penetrate the middle layer of the skin and that cause up to 90% of skin aging, along with a smaller amount of UVB rays that are responsible for sunburns .

The sun protection factor, or SPF, rating on American sunscreen bottles denotes only a sunscreen’s ability to block UVB rays. Although American sunscreens labeled “broad spectrum” should, in theory, block UVA light, some studies have shown they fail to meet the European Union’s higher UVA-blocking standards.

“It looks like a number of these newer chemicals have a better safety profile in addition to better UVA protection,” said David Andrews , deputy director of Environmental Working Group, a nonprofit that researches the ingredients in consumer products. “We have asked the FDA to consider allowing market access.”

The FDA defends its review process and its call for tests of the sunscreens sold in American stores as a way to ensure the safety of products that many people use daily, rather than just a few times a year at the beach.

“Many Americans today rely on sunscreens as a key part of their skin cancer prevention strategy, which makes satisfactory evidence of both safety and effectiveness of these products critical for public health,” Cherie Duvall-Jones, an FDA spokesperson, wrote in an email.

D’Ruiz’s company, DSM-Firmenich, is the only one currently seeking to have a new over-the-counter sunscreen ingredient approved in the United States. The company has spent the past 20 years trying to gain approval for bemotrizinol , a process D’Ruiz said has cost $18 million and has advanced fitfully, despite attempts by Congress in 2014 and 2020 to speed along applications for new UV filters.

Bemotrizinol is the bedrock ingredient in nearly all European and Asian sunscreens, including those by the South Korean brand Beauty of Joseon and Bioré , a Japanese brand.

D’Ruiz said bemotrizinol could secure FDA approval by the end of 2025. If it does, he said, bemotrizinol would be the most vetted and safest sunscreen ingredient on the market, outperforming even the safety profiles of zinc oxide and titanium dioxide.

As Congress and the FDA debate, many Americans have taken to importing their own sunscreens from Asia or Europe, despite the risk of fake products .

“The sunscreen issue has gotten people to see that you can be unsafe if you’re too slow,” said Alex Tabarrok , a professor of economics at George Mason University. “The FDA is just incredibly slow. They’ve been looking at this now literally for 40 years. Congress has ordered them to do it, and they still haven’t done it.”

KFF Health News is a national newsroom that produces in-depth journalism about health issues and is one of the core operating programs at KFF—an independent source of health policy research, polling, and journalism. Learn more about KFF .

Home › Skin Cancer Prevention › Sun Protection › Sunscreen

All About Sunscreen

Why you need it. how it works for you..

The big picture: Sunscreen is an important part of a complete sun protection strategy to safeguard your skin against sun damage and skin cancer. But sunscreen alone isn’t enough to keep you safe in the sun.

When used as directed, sunscreen can:

Decrease your risk of skin cancers and skin precancers. Studies show that regular daily use of SPF 15 sunscreen, when used as directed, can reduce your risk of developing squamous cell carcinoma (SCC) by about 40 percent, and lower your melanoma risk by 50 percent.

Help prevent premature skin aging caused by the sun, including wrinkles, sagging and age spots.

Watch video: How to read a sunscreen label

Who should use sunscreen?

• What type of sunscreen should I use?

When should I apply sunscreen?

Where should i apply sunscreen, how much sunscreen should i use, why should i use sunscreen, know the 5 w’s (& h) of sunscreen.

WHO : Everyone under the sun WHAT : Broad spectrum SPF 15 or higher; SPF 30 or higher for a day outdoors WHEN : Every day; 30 minutes prior to going outdoors. Reapply every two hours WHERE : All exposed skin HOW : One ounce (shot glass full) to entire body for each application WHY : Reduce your risk of skin damage and skin cancer!

The short answer is everyone ! Men, women and children over 6 months of age should use sunscreen every day. This includes people who tan easily and those who don’t — remember, your skin is damaged by sun exposure over your lifetime, whether or not you burn.

Babies under the age of 6 months are the only exceptions; their skin is highly sensitive. Stay out of the sun; shade structures and sun-protective clothing are the best ways to safeguard infants.

What type of sunscreen should you use?

With so many choices, how do you pick a sunscreen that’s right for you? The Skin Cancer Foundation believes that the best sunscreen is the one you are most likely to use, so long as it provides safe and effective protection, and is broad spectrum with an SPF 15 or higher. Learn about your options to make an informed choice that best suits your needs. The happier you are with your sunscreen, the more consistently you’ll use it.

Sunscreen ingredients

Sunscreen includes active ingredients that help prevent the sun’s UV radiation from reaching your skin. Here’s how the two types of sunscreen work for you:

Physical (mineral) sunscreen ingredients (including the minerals titanium dioxide and zinc oxide) block and scatter the rays (like a shield) before they penetrate your skin.

Chemical sunscreen ingredients (like avobenzone and octisalate) absorb UV rays (like a sponge) before they can damage your skin.

Are sunscreens safe?

While physical sunscreens may be less likely to cause skin irritation than chemical sunscreens, both types have been tested as safe and effective. In fact, many sun protection products available today combine both types of ingredients.

All active ingredients in sunscreen are chemically derived.  Some people may think of physical sunscreens as more “natural,” or even “organic,” but they’re actually inorganic mineral compounds. The sunscreens many people call “chemical” are actually “UV organic filters.”

What does SPF mean?

SPF stands for Sun Protection Factor . The number tells you how long the sun’s UVB rays would take to redden your skin if you apply the sunscreen exactly as directed compared with the amount of time without sunscreen. So, if you use an SPF 30 product properly, it would take you 30 times longer to burn than if you used no sunscreen.

What level of SPF do I need? If you’re inside most of the day with just short intervals in the sun, you can use a sunscreen or cosmetic product with an SPF of 15 or higher. If you spend a lot of time outdoors, especially when and where the sun is strongest, you need an SPF 30 or higher, water-resistant sunscreen. More about SPF .

No matter the SPF , reapplication every two hours is key. Sunscreen must also be reapplied immediately after swimming or sweating.

Broad-spectrum protection

In the past, most sunscreens only included information on product labels about protection against UVB  — the rays that cause sunburn, and not UVA — the rays that cause tanning and premature aging. Now that UVA dangers are well known, broad-spectrum sunscreen provides clear information on product labels about protection against both UVB and UVA.

Choosing a sunscreen: What to look for

Broad spectrum: Protects your skin from both UVA and UVB rays.

Water resistant and very water resistant: For swimming or intense exercise. No sunscreen is waterproof; they all eventually wash off. Sunscreens labeled water resistant are tested to be effective for up to 40 minutes of swimming, while very water resistant sunscreens stay effective for up to 80 minutes in the water.

Every day! The best practice is to apply 30 minutes before venturing outside to allow the sunscreen to bind to your skin. Reapply every two hours and immediately after swimming or excessive sweating.

Even when it’s cloudy , up to 80 percent of the sun’s UV radiation reaches the earth. Going unprotected on an overcast day can lead to skin damage.

Experts recommend applying sunscreen to your entire body before you dress for the day. That way your skin will be protected if your clothing shifts or you remove layers. At the very least, you should use sunscreen on every part of your body that is exposed to the sun, including those easy-to-miss spots: the tops of your ears, back of your neck, your scalp (on the part line), tops of your feet and behind your knees.

To get the full broad-spectrum protection out of your sunscreen, apply one ounce — about a shot glass full — to your entire body. Most people apply less than half of that amount, translating into reduced protection. Learn more .

With reapplication, a family of four should use one four-ounce bottle of sunscreen per person during a long day outdoors.

Sunscreen reduces your overall UV exposure and lowers your risk of skin cancer and sun damage.

Other things to consider

• Your skin cancer risk factors : Your skin type and family history will determine the level of protection needed for you.
• Photosensitivity : No matter your skin type, certain medications and disorders make your skin highly sensitive to the sun, raising your protection requirements.
• Skin conditions : You can choose from sunscreens for dry skin, oily skin, acne-prone skin and sensitive skin.

Live a sun-safe life

Keep in mind that while crucial, sunscreen alone is not enough . Seek the shade whenever possible, wear sun-safe clothing, a wide-brimmed hat and UV-blocking sunglasses, for a complete sun safety strategy.

To help you select sun-safe products, look for the Skin Cancer Foundation’s Seal of Recommendation and browse our recommended sunscreen products .

For more prevention tips, see Your Daily Sun Protection Guide .

Video: How to read a sunscreen label

Reviewed by: Elisabeth G. Richard, MD

Last updated: July 2022

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Sunscreens and Photoaging: A Review of Current Literature

• Review Article
• Published: 13 August 2021
• Volume 22 , pages 819–828, ( 2021 )

Cite this article

• Linna L. Guan 1 ,
• Henry W. Lim 1 &
• Tasneem F. Mohammad 1  

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Sunscreens have been on the market for many decades as a means of protection against ultraviolet-induced erythema. Over the years, evidence has also shown their efficacy in the prevention of photoaging, dyspigmentation, DNA damage, and photocarcinogenesis. In the USA, most broad-spectrum sunscreens provide protection against ultraviolet B (UVB) radiation and short-wavelength ultraviolet A (UVA) radiation. Evidence suggests that visible light and infrared light may play a role in photoaging and should be considered when choosing a sunscreen. Currently, there is a paucity of US FDA-approved filters that provide protection against long UVA (> 370 nm) and none against visible light. Additionally, various sunscreen additives such as antioxidants and photolyases have also been reported to protect against and possibly reverse signs of photoaging. This literature review evaluates the utility of sunscreen in protecting against photoaging and further explores the requirements for an ideal sunscreen.

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1 Introduction

Chronic sun exposure has long been known to cause photoaging, a process where the skin undergoes changes in epidermal thickness, increases in pigment heterogeneity and dermal elastosis, degradation of collagen in the dermis, development of ectatic vessels, and increases in mutagenesis of keratinocytes and melanocytes in the skin [ 1 ]. Clinically, this is characterized by an increase in rhytides, telangiectasias, dyspigmentation including lentigines and ephelides, volume loss, and cutaneous malignancies [ 1 ]. A recent observational study further characterized skin aging as hypertrophic and atrophic variants, with atrophic photoaging presenting with erythema and increased risk of skin cancers and hypertrophic photoaging with increased skin thickness and sallowness [ 2 ].

In today’s society, the value placed on a youthful appearance is reflected in the multibillion-dollar industry centered around anti-aging products [ 3 , 4 ]. It has been reported that approximately 80% of skin aging on the face can be attributed to ultraviolet (UV) exposure [ 5 ]. Therefore, despite the emphasis of the market on the reversal of skin aging, the best defense against cutaneous age-related changes is through prevention with rigorous photoprotection [ 4 ]. It should be noted that proper photoprotection consists of seeking shade when outdoors; wearing a wide-brimmed hat, photoprotective clothing, and sunglasses; and applying sun protection factor (SPF) ≥ 30 broad-spectrum tinted sunscreen on exposed sites.

In the USA, most broad-spectrum sunscreens provide protection against UVB radiation and short wavelength UVA radiation. However, there is a paucity of US FDA-approved filters that provide protection against long UVA (> 370 nm) and none against visible light (VL), making the ideal sunscreen a product that requires further innovation and research. Notable exceptions are pigmentary grade zinc oxide and titanium dioxide, which reflect VL; however, the whitish discoloration they leave on the surface of the skin makes them cosmetically unappealing to consumers. This review evaluates the utility of sunscreen in protecting against photoaging and further explores the requirements of an ideal sunscreen.

2 Electromagnetic Radiation and Photoaging

Solar UV radiation (UVR) consists of UVA (320–400 nm), UVB (280–320 nm), and UVC (100–280 nm). UVA is further categorized as UVA1 (340–400 nm) and UVA2 (320–340 nm). UVC is the shortest wavelength and considered the most damaging type of UVR. However, it is completely absorbed by the ozone and does not reach the earth’s surface [ 6 ].

UVB is the major portion of UVR that induces sunburns or UV-induced erythema. It is known to be significantly more erythemogenic than UVA [ 6 ]. For example, for skin phototype I, the minimal erythema dose for UVB is 20–40 mJ/cm 2 , whereas that for UVA is 20–40 J/cm 2 . Although UVB accounts for approximately 6% of all UVR that reaches the earth’s surface, it is more cytotoxic than UVA, causing direct DNA damage through photon absorption in the form of cyclobutane pyrimidine dimers (CPDs) or 6,4-photoproducts that eventually induce mutagenesis and skin cancers [ 7 , 8 ]. UVB has been shown to be highly associated with the development of squamous cell carcinomas [ 9 ]. Additionally, even suberythemal doses of UVB have been shown to induce CPD formation and therefore increased p53 expression as cells undergo apoptosis or repair [ 10 ]. UVB has also been shown to induce matrix metalloproteinases (MMPs), reactive oxygen species (ROS), and elastases involved in photoaging [ 11 ].

UVB is predominantly absorbed by the skin’s epidermis, whereas UVA has a longer wavelength and therefore deeper dermal penetration, making it the primary driver of photoaging [ 12 ]. Although UVA is lower in energy than UVB, it is approximately 20 times more abundant in the earth’s atmosphere and is not blocked by glass [ 13 ]. The ratio of UVB/UVA varies by season [ 14 ]. Studies of UVA on skin models demonstrated that UVA caused the induction of apoptosis in dermal fibroblasts and increased MMP levels, which are enzymes involved in collagen degradation [ 12 , 15 ]. Additionally, repeat exposure to UVA on in vivo human skin induced elevated markers of photoaging, such as ferritin and lysozyme, which are involved in the oxidative stress response and elastin degradation, respectively [ 16 ]. In a study looking at asymmetric UVA exposure of the face, chronic exposure to UVA significantly affected the clinical level of wrinkling and roughness of the skin [ 17 ]. Furthermore, in a study of 22 participants exposed to multiple sessions of low-dose UVA1, increasing levels of MMP-1 and MMP-3 were observed in a dose-dependent response in the dermis, further highlighting the role of UVA in collagen breakdown and photoaging [ 13 ]. In skin of color, UVA has been shown to induce irregular spotty pigmentation associated with photoaging [ 12 ].

However, the effects of UVA and UVB are not always distinct, as overlapping cutaneous biologic effects have been observed. UVA has been shown to induce CPDs through ROS generated by photo-activation of UVA-absorbing molecules (chromophores) in the skin such as riboflavin, porphyrins, and heme-containing proteins [ 18 ]. Similarly, UVB has also been shown to induce dermal fibroblast senescence [ 19 ].

There is increasing evidence that infrared light (IR; 700 nm–1 mm) and VL (400–700 nm), predominantly in the blue light range (380–455 nm), play a role in photodamage and photoaging. Studies have demonstrated that VL can independently generate ROS, proinflammatory cytokines, and MMP-1 expression and potentiate the effects of UVR [ 20 , 21 , 22 , 23 ]. Effects of photoaging have also been observed with irradiation of skin within the UV/VL boundary region (385–405 nm), demonstrating differential expression of genes involved in inflammation, oxidative stress, and photoaging when compared with nonirradiated skin [ 24 ]. Likewise, in vivo skin irradiated with IR and VL has shown significantly increased MMP-1 and MMP-9 expression and decreased type I procollagen expression, implicating IR and VL light in the degradation of dermal collagen [ 25 ]. Moreover, studies have demonstrated that there is a synergistic relationship between even small amounts of UVA1 and VL in the induction of increased and prolonged pigmentation [ 21 , 26 ]. This suggests that VL and IR may play a significant but underreported role in photoaging and dyspigmentation.

Although the exact mechanisms are not yet fully understood, increasing literature indicates a need for photoprotection against the broad spectrum of electromagnetic radiation (UV, VL, and IR) to prevent photoaging.

3 Role of Sunscreens in Photoaging

The concept of a topical photoprotective product has been around since the times of the ancient Egyptians in 4000 BC, but the first commercial sunscreens were not available until the 1920–1930s [ 27 , 28 ]. At that time, understanding of UV radiation was limited and focused mainly on UVB protection. With the increasing popularity of sunscreen over the years, the concept of standardization of photoprotection against UVB was introduced [ 27 ]. SPF was recognized by the FDA in 1978 as the standard for measuring sun protection [ 27 ].

UV-induced erythema is mostly attributed to UVB, with a minor contribution by UVA2. The concept of SPF, an assessment using UV-induced erythema as an endpoint, as a sole measurement of sun protection persisted for many decades despite advances in the study of UVR suggesting that UVA may play a significant role in photoaging [ 27 , 29 , 30 ]. In 1992, the UVA star rating system was created by The Boots Company in the UK but was not widely implemented [ 27 ]. Although other methods of evaluating the efficacy of UVA filters have been proposed, the FDA currently uses critical wavelength (CW) determination. With this method, sunscreen products whose 90% UV absorbance occurs at ≥ 370 nm are allowed to be labeled as “broad spectrum” [ 31 ]. In Europe, the International Organization Standardization 24443 guidelines use a minimum ratio of UVA protection factor to SPF of 1:3 for all marketed sunscreens [ 32 ]. In a study of 20 sunscreens tested against the FDA guidelines and the ISO 24443 guidelines, 19 of 20 sunscreens met the CW requirements set by the FDA, whereas only 11 of 20 sunscreens met the ISO 24443 standard [ 31 ]. To address this disparity, the FDA proposed a new rule on sunscreens in 2019 that specifically highlighted a requirement for a UVA1 (340–400 nm) to UVA and UVB (290–400 nm) ratio of ≥ 0.7; however, the FDA has not yet made a final decision [ 33 ]. Clearly, there exists further need for global standardization to help protect and guide consumers.

In recent years, tinted sunscreens have become more prevalent as a means of protection against VL. Most FDA-approved compounds for UV protection do not adequately protect against VL because compounds must be opaque to filter VL [ 34 ]. Zinc oxide and titanium dioxide can protect against VL but only when they are pigmentary grade and not micronized. Tinted sunscreens incorporate combinations of iron oxides and pigmentary titanium dioxide to offer VL protection and utilize the different colors of iron oxides and pigmentary titanium dioxide to improve color match on people of all Fitzpatrick skin types [ 34 , 35 ]. It should be noted that iron oxides are not considered to be UV filters so are listed under “inactive ingredients” on sunscreen product packages, whereas pigmentary-grade titanium dioxide and zinc oxide are FDA-approved inorganic filters. However, the exact efficacy of specific tinted sunscreens for VL protection has been largely unregulated as no standards or guidelines for VL protection yet exist. A method for VL protection factor has been recently suggested using in vivo assessment in melano-competent subjects [ 22 , 36 ].

There is good evidence that daily photoprotection and daily sunscreen use plays an important role in the prevention of photoaging [ 37 , 38 ]. In a study of 46 patients randomly selected to use vehicle or sunscreens with UVA and UVB protection daily for 24 months, a significant histological difference in solar elastosis was observed in the vehicle versus treatment group [ 38 ]. Furthermore, in a study of 12 subjects in which each subject was exposed to one minimal erythemal dose of simulated solar radiation to three areas of buttock skin (unprotected skin, vehicle, and day cream with UVA and UVB protection) and control (no exposure), the unprotected skin demonstrated significant melanization, increased stratum corneum and stratum granulosum thickness, elevated expression of tenascin, reduced type I procollagen, and slightly increased lysozyme and alpha-1 antitrypsin, which were all mitigated by the day cream–sunscreen combination [ 39 ]. Not only have sunscreens been shown to prevent photoaging but evidence also suggests that they may play a role in the reversal of extrinsic aging. In a prospective study, 32 subjects were asked to apply daily broad-spectrum photostable sunscreen (SPF 30) for 52 weeks. At the end of the study, significant improvements in skin texture, clarity, and mottled and discrete pigmentation were observed, with 100% of subjects showing improvement in skin clarity and texture [ 40 ]. However, further research into the molecular mechanism of sunscreen’s effects on the reversal of chronologic aging must be performed.

4 Challenges and Limitations of Current Sunscreens

Sunscreen technology has made great advancements in accessibility, consumer acceptability, and overall safety and efficacy over the years. However, the challenges and limitations of current sunscreens leave room for further research and innovation. In the evaluation of sunscreens available for US consumers today, FDA regulations, safety in humans, and safety for the environment must be carefully considered.

In the 2019 proposed rule on sunscreens, the FDA proposed to categorize sunscreen filters as category I—“GRASE” (Generally Recognized as Safe and Effective), category II—non GRASE, or category III—requires further evaluation (Table 1 ) [ 41 ]. Currently, only two UV filters are category I: titanium dioxide and zinc oxide [ 42 ]. Both of these inorganic filters work by scattering, reflecting, and absorbing UV. The aggregation of these particles on the skin means they tend to leave a whitish hue on the skin that is unacceptable for many consumers, especially those with skin of color [ 43 , 44 ].

In the 2019 FDA-proposed rule, two ingredients, para-aminobenzoic acid (PABA) and trolamine salicylate, were classified as category II and banned from products marketed in the USA given their safety concerns. PABA has been linked to cases of allergic and photoallergic dermatitis and is a cross-sensitizer to sulfonamide antibiotics, thiazide diuretics, local anesthetics, and dyes [ 42 ]. Trolamine salicylate is a salicylate class of UV filters and has been linked to systemic absorption and increased risk of bleeding and salicylate toxicity [ 42 ]. It should be noted that neither of these has been used in the US market for years, so this categorization does not affect the US market.

Organic UV filters, dioxybenzone, sulisobenzone, oxybenzone, avobenzone, cinoxate, octinoxate, octisalate, homosalate, padimate O, ensulizole, meradimate, and octocrylene have now been categorized as category III, which means that additional data to determine the general recognition of safety is needed [ 42 ]. Organic UV filters absorb the higher energy of UV rays and emit a lower thermal energy [ 41 , 45 ]. It should be noted that the FDA is only requesting safety data for these 12 filters and did not question the efficacy of UV filters. None of the 12 category III UV filters offer effective visible light protection, and only meradimate and avobenzone offer partial UVA1 protection [ 41 ].

The organic UV filters can be categorized into cinnamates, benzophenones, salicylates, PABA derivatives, and others. Octinoxate, a cinnamate, is the most common sunscreen ingredient in the USA. It is photolabile and is often combined with other UVB absorbers to increase both its final SPF and its photostability [ 46 ].

The benzophenones include dioxybenzone, sulisobenzone, oxybenzone, and avobenzone, with oxybenzone the most commonly used agent in the group [ 46 ]. Although benzophenones have been shown to be effective UVA filters, their lack of photostability requires them to be compounded with other filters such as octocrylene, salicylates, micronized zinc oxide, and titanium dioxide to improve their photostability [ 44 , 46 , 47 ]. Additionally, oxybenzone is the most common photoallergen of the UV filters.

The salicylates octisalate and homosalate are only weak UVB absorbers and are mainly used in sunscreens as photostabilizers in combination with other organic filters [ 46 ]. Padimate O is a PABA derivative; like its predecessor, it has potent UVB filtration but is rarely used [ 44 , 46 ]. Ensulizole is primarily a UVB filter with minimal UVA2 activity [ 48 ]. Meradimate is a weak UVA blocker and has no activity against UVB [ 41 , 46 ]. Octocrylene is a photostable UVB and UVA2 filter primarily used as a photostabilizer in conjunction with other filters [ 46 ]. Ecamsule (Mexoryl SX) is an effective UVA filter that has been shown to be effective against photoaging when combined with UVB filters [ 49 ]. It has been approved via the new drug application process, with its use as an active ingredient permitted only in certain products under specific concentrations [ 41 , 43 , 44 ].

Although other photostable and more effective broad-spectrum UV filters, including bemotrizinol, bisoctrizole, and drometrizole trisiloxane, are available in other countries, these agents—along with many other UV filters available in other countries—are still pending FDA approval in the USA [ 27 , 41 ]. In over a decade, no new UV filters have been approved by the FDA to be added to the 16 currently approved filters. In contrast, the European Commission currently has 27 approved UV filters [ 27 ]. However, with the Coronavirus Aid, Relief, and Economic Security (CARES) Act signed into law in March 2020, the FDA has been mandated to move from a laborious rulemaking process to an administrative order process, which means it should not take as long to implement a monograph. The FDA is to issue a new proposed administrative order by 27 September 2021. Once the final administrative order has been enacted, industry has 12 months to comply. In addition, the CARES Act also incentivizes innovation by providing an 18-month exclusivity period to the requesting manufacturer of a new filter [ 50 ].

Controversy regarding organic sunscreen safety in humans has increasingly been a topic of discussion after studies showed systemic absorption of six commonly used sunscreen active ingredients [ 51 , 52 ]. This 2020 study of 48 randomized participants applying 2 mg/cm 2 of sunscreen product to 75% of body surface areas between one and four times per day for 4 days demonstrated systemic absorption of avobenzone, oxybenzone, octocrylene, homosalate, octisalate, and octinoxate [ 51 ]. However, a systematic review of 29 studies looking at the effects of two of the most commonly studied sunscreen ingredients—oxybenzone and octinoxate—demonstrated that oxybenzone had no adverse effects on male and female fertility, female reproductive hormone levels, adiposity, fetal growth, childhood neurodevelopment, or sexual maturation, and octinoxate had no effect on thyroid and reproductive hormone levels [ 53 ]. Although the review recommended further research into the effects of oxybenzone levels on thyroid hormone, testosterone level, kidney function, and pubertal timing, the evidence is not yet sufficient to support a causal relationship between the elevated systemic levels of oxybenzone or octinoxate and adverse health outcomes. Further longitudinal randomized controlled studies should be performed before factoring the biological effects of systemically absorbed agents into clinical and practical guidelines [ 54 , 55 ]. A recent report by Valisure LLC, an independent laboratory, also raised safety concerns regarding benzene in sunscreen products. After testing multiple batches of 69 brands of sunscreen and after-sun skincare products, they found that 78 batches contained elevated levels of benzene, a carcinogen known to cause leukemia and lymphoma [ 56 ]. It is important to note that both organic and inorganic sunscreens and some cosmetic products that did not contain any UV filters were among the contaminated products. In addition, many sunscreen products tested did not contain benzene. The report concluded that the contamination was due to supply chain issues in the manufacturing process rather than degradation of sunscreen filters. These findings led to an FDA citizen petition for the recall of identified batches of sunscreen with elevated levels of benzene and further investigation into these products and their manufacturing processes. A full report, including a list of products tested, can be found on the Valisure website [ 57 ].

Additionally, the National Oceanic and Atmospheric Administration identified ten sunscreen ingredients as being toxic to coral and marine life: oxybenzone, benzophenone-1, benzophenone-8, PABA, 4-methylbenzylidene camphor, 3-benzylidene camphor, nano-titanium dioxide, nano-zinc oxide, octinoxate, and octocrylene [ 58 ]. Studies that demonstrated marine toxicity were performed in vitro with high concentrations of sunscreen ingredients [ 44 , 55 , 59 ]. In a review looking at all 32 published studies until June 2020, 14 different organic UV filters in seawater near coral reefs were detected in the nanograms per liter range, in contrast to toxic levels in the micrograms per liter to milligrams per liter range reported in nine papers [ 60 ]. This puts the toxic levels of organic UV filters at 1000- to 1 million-fold higher concentrations than currently reported. Although 27 of the 32 reviewed studies showed no risk of UV filters to coral reefs, three studies of oxybenzone and octinoxate demonstrated a few data points where some risk was present [ 54 ]. This reflects the major data gaps that immediately need to be addressed with high-quality monitoring and toxicity studies applicable to the real world. To address this issue, on 9 February 2021, the National Academies formed a committee sponsored by the Environmental Protection Agency to study the environmental and health impacts of sunscreens. Although data supporting that the coral reefs are adversely impacted by environmental exposure to UV filters are limited, the state of Hawaii banned sunscreens containing oxybenzone and octinoxate in 2018, and Key West, Florida, USA, did the same in 2019 [ 59 ].

Although FDA guidelines aim to protect US consumers from harm, it has also greatly diminished the variety of UV filters available to consumers. Newer and more effective broad-spectrum UV filters are available in other countries but are not currently FDA approved [ 41 ]. With the new proposed administrative order under the CARES Act and careful consideration of human safety, environmental safety, photostability, and consumer cosmesis, the development and approval of new sunscreens that are effective against UVA, UVB, and VL must be considered for protection against photoaging.

5 Additives in Sunscreens

With the rise of cosmeceuticals and additives in sunscreens, it is important to evaluate the safety and efficacy of these substances. Although the exact mechanism of UVR- and VL-induced photoaging is still being explored, the downstream effects of increased ROS, MMPs, and DNA damage have been widely reported [ 8 , 11 ]. To combat the deleterious effects of sunlight on the skin, additives have been used or proposed in sunscreens to enhance photoprotection and help prevent photoaging.

Antioxidants play an important role in preventing, ameliorating, and dampening free radicals and oxidative stress. Although our bodies produce natural antioxidants, UVR and other stressors can often overwhelm our endogenous supply [ 61 ]. Topical antioxidants have been formulated into sunscreens to replenish depleted antioxidant supplies and diminish oxidative stress on the skin. Yet the exact role and efficacy of antioxidants in sunscreens remains controversial. A 2011 ex vivo study by Wang et al. [ 62 ] evaluated the radical skin protection factor (RSF) and antioxidant power (AP) of 12 sunscreen products containing vitamin C, vitamin E, or other antioxidant substances against simulated UVA- and UVB-induced ROS. RSF was defined as the ratio of free radicals in unprotected skin to protected skin, and AP evaluates the capacity and reaction time of antioxidants by measuring free electron spin [ 62 ]. They demonstrated that the RSF correlated with the UVA RSF rather than any antioxidant ingredients [ 62 ]. However, the study was performed ex vivo and may not correlate to in vivo responses in humans. More recent reviews and studies have demonstrated positive effects of the addition of antioxidants into sunscreen formulations. For example, a study looking at skin irradiated with UVB found that sunscreens with SPF 25 and a mixture of caffeine, vitamin E, vitamin C, Echinacea pallida extract, gorgonian extract, and chamomile essential oil demonstrated less MMP-1 expression than those with only SPF 25 [ 63 ]. The variability in the efficacy of antioxidants in sunscreens may depend on the formulation of the sunscreen. It has been proposed that, for antioxidants to be efficacious, they must have high antioxidative capacities, be present in high concentrations, be stable in the final formulation, and be able to penetrate the stratum corneum and still exist at high enough concentrations in the epidermis and dermis to be effective [ 61 ].

In terms of antioxidants that have been explored in topical formulations, vitamin C ( l -ascorbic acid) is the predominant antioxidant in the skin and plays an important role in the skin’s aqueous compartments because of its water solubility [ 61 ]. It also helps replenish vitamin E, acts as a cofactor in collagen synthesis, and reduces elastin accumulation [ 61 ]. It is not synthesized by the human body and must be replenished via oral intake [ 64 ]. Additionally, because of its ionic charge at physiologic pH, it cannot penetrate the stratum corneum without becoming unstable. Fortunately, a stable formulation can be made by compounding it with other antioxidants: vitamin E (alpha-tocopherol) and ferulic acid [ 61 , 64 ]. Murray et al. [ 65 ] demonstrated that skin irradiated with solar-simulated UVR after application of a topical formulation of 15% l -ascorbic acid, 1% alpha-tocopherol, and 0.5% ferulic acid (CEFer) for 4 days significantly decreased UV-induced erythema, sunburn cells, thymine dimers, and p53 induction when compared with untreated skin. Furthermore, vitamin E has been shown to be effective in the reduction of lipid peroxidation, photoaging, immunosuppression, and photocarcinogenesis in multiple animal and human studies [ 61 ]. This suggests a role for topical CEFer in protecting against photoaging and skin cancers [ 64 , 65 ].

Vitamin A and its derivatives, mainly retinoids and carotenoids, have been well studied in the realm of antiaging and have shown benefit in the prevention and reversal of photoaging [ 66 ]. They bind to cytoplasmic receptors such as cellular retinoic acid-binding protein types I and II and cellular retinol-binding protein as well as nuclear receptors such as nuclear retinoic acid receptors and retinoid X receptors to inhibit activation of protein-1 and MMP-1 expression [ 61 ]. This leads to increased epidermal proliferation, leading to epidermal thickening, compaction of the stratum corneum, synthesis and deposition of glycosaminoglycans, and increased collagen production [ 61 , 67 ]. Furthermore, there is evidence that topical retinoids may play a role in chemoprevention of nonmelanoma skin cancers through initiating growth arrest of tumor cells and normal cellular differentiation [ 68 ]. However, given the relative instability of retinol and retinoids when exposed to UV and visible light, their use as a sunscreen additive is predominantly for their anti-aging effects and not for increased photoprotection. They are rarely found in recreational sunscreens, and their stability is highly dependent on their formulation and chemical structure. For example, when tretinoin is compounded in ethanol, it undergoes isomerization within just a few seconds when irradiated with light of 300–800 nm [ 69 ]. The stability of tretinoin is improved when incorporated into liposomes [ 69 ]. Retinyl palmitate is an ester of retinol that is widely used in cosmetic products because of their high thermal stability when compared with retinol [ 70 ]. A study of 11 healthy volunteers using two formulations of retinyl palmitate for 60 days reported significant improvements in skin smoothness, skin roughness, scaliness, and wrinkles with both formulations [ 71 ]. Retinyl palmitate can be compounded with photostabilizers and UV filters and loaded onto nanotechnology-based drug-delivery systems to improve stability and drug penetration, but large-scale randomized controlled trials are needed to study the antiaging properties of these formulations [ 70 , 72 ]. Additionally, concerns have been raised regarding an increase in cutaneous malignancy with simultaneous use of topical retinyl palmitate and UVR exposure. A recent study looking at SKH-1 hairless mice treated with control cream or creams containing retinyl palmitate and subsequently irradiated with simulated solar light demonstrated an increased risk of photo-co-carcinogenesis in the group using cream containing retinyl palmitate [ 73 ]. However, these claims have not been largely substantiated or reported in humans and need to be further studied.

Other antioxidants that have been reported in the literature include soy extracts, polyphenols, melatonin, algae extract, and Polypodium leucotomos extract [ 30 ]. A study of 68 participants observed that soy moisturizer containing soybean-derived serine protease inhibitors (soybean trypsin inhibitor and Bowman–Birk protease inhibitor) significantly improved mottled pigmentation, blotchiness, dullness, fine lines, overall texture, overall skin tone, and overall appearance when compared with vehicle [ 74 ]. This positive clinical effect may be related to the role of soybean-derived serine protease inhibitors on the regulation of keratinocytes through keratinocyte protease-activated receptor 2, but additional studies must be performed to further elucidate its mechanism [ 74 ].

Polyphenols are found in many botanicals, including tea leaves, grape seeds ( Vitis vinifera ), blueberries, almond seeds, and pomegranate extract [ 75 ]. In a study of five participants, sunscreen compounded with tea extracts containing polyphenols such as epigallocatechin-3-gallate better protected human skin against solar-simulated UVR over sunscreen alone in regards to decreasing MMP-1 [ 63 ]. Additionally, green tea extract compounded with resveratrol, another polyphenol, provided SPF protection independent of physical and chemical UV filters, but additional in vivo studies must be performed to fully assess its effectiveness [ 76 ].

Melatonin acts as an antioxidant in three different but complementary ways. It can act as a free radical scavenger, decrease free radical generation, and upregulate antioxidant enzymes [ 77 ]. It has shown promise against both UVB- and UVA-induced oxidative stress. In studies of human melanocytes and keratinocytes, cells pretreated with melatonin decreased p53 expression, improved DNA repair, and decreased CPD generation [ 78 , 79 ]. An in vitro study of mouse fibroblast cells (NIH3T3) pretreated with melatonin and irradiated with UVA demonstrated increased heme-degrading enzymes and suppression of UVA-induced photodamage when compared with untreated irradiated cells [ 77 ]. Additionally, melatonin protected against UV-induced erythema and activated endogenous enzymes to act against oxidative stress [ 75 ]. This suggests a potential role of melatonin as an additive to protect keratinocytes, melanocytes, and fibroblasts against UV-induced photoaging.

Many studies have shown that multicellular algae not only have UV-absorbing properties but also provide benefits against oxidative stress [ 75 ]. Mycosporine-like amino acids (MAAs) produced by algae are potent UV filters with maximum absorption between 310 and 362 nm [ 80 ]. Shinorine is a commercialized MAA extracted from a type of red algae, Porphyra umbilicalis, and has already been used in sunscreens produced by two European companies [ 81 ]. Furthermore, the algae and algae products have also demonstrated protective properties against photoaging. Alga  Corallina pilulifera  methanol extract reduced MMP-2 and MMP-9 in UV-irradiated human dermal fibroblasts [ 82 ]. Additionally, many species of brown algae are protective against photo-oxidative stress [ 75 ]. With controversies around chemical sunscreens and their effects on marine life, algae-derived sunscreens may provide a future solution for eco-friendly photoprotection; however, most formulations of sunscreens with MAAs currently contain only a very small percentage of this active ingredient, and it functions as an adjuvant to UV filters and other sources of photoprotection [ 83 ].

Polypodium leucotomos extract (PLE) is derived from a tropical fern found in Central and South America and has antioxidative, chemoprotective, immunomodulatory, and anti-inflammatory effects [ 84 , 85 ]. In a recent study of 22 individuals irradiated with UVB, UVA, and VL, oral PLE demonstrated suppressive effects on UVB-induced erythema within 2 h of administration [ 84 ]. Oral PLE demonstrated similar photoprotective effects against VL. In a cross-over study, subjects taking PLE 480 mg daily demonstrated a significant decrease in persistent pigment darkening, delayed tanning, and cyclooxygenase-2 compared with pre-PLE [ 86 , 87 ]. Oral PLE should be taken daily to receive benefit and is meant to be an adjuvant to sunscreen, not a replacement. Topical formulations of PLE were also effective in reducing sunburn cells and reducing CPD in an in vitro reconstructed human epidermis model [ 87 ]. However, future in vivo studies must be performed to better assess the feasibility of topical PLE as a sunscreen additive.

In addition to antioxidants, photolyases are also beneficial additives in sunscreens. Photolyases are enzymes with a unique ability to repair DNA damage, specifically CPDs. They are flavoproteins and require flavonoids as cofactors to absorb UV radiation. The absorbed energy from UV radiation is then transferred to damaged DNA to break CPD bonds in both in vivo and in vitro studies [ 30 ]. It also significantly reduced markers of photoaging when added to SPF 50 sunscreen and antioxidants compared with sunscreen alone or sunscreen and antioxidants [ 88 ]. This suggests that photolyases may synergistically enhance the photoprotective effects of sunscreens and antioxidants [ 30 ].

The perception of sunscreen use has shifted from purely protecting against UV-induced erythema to broad-spectrum protection against not only erythema but also photoaging, dyspigmentation, DNA damage, and photocarcinogenesis. The impact of visible light and IR light in photoaging is still being explored, but better methods of protection against these wavelengths are needed. Sunscreens continue to be adapted to provide the broadest coverage while being cosmetically appealing. However, with the increased scrutiny of UV filters in the 2019 FDA proposed rule, new UV filters that are safe for humans and the environment, photostable, and consumer friendly must be developed and approved to offer continued sun protection for US consumers. When choosing a sunscreen, a broad-spectrum tinted sunscreen with SPF ≥ 30 used daily will offer protection against UVR and VL to reduce their effects on photoaging. Additionally, sunscreen additives such as antioxidants, photolyases, and more have opened the door for not only improved photoprotection against but also the reversal of skin aging. However, larger-scale and replicable studies must be performed before clinical guidelines can be issued.

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Guan, L.L., Lim, H.W. & Mohammad, T.F. Sunscreens and Photoaging: A Review of Current Literature. Am J Clin Dermatol 22 , 819–828 (2021). https://doi.org/10.1007/s40257-021-00632-5

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What’s the Best Kind of Sunscreen?

S unscreen is a $10 billion business , with a seemingly endless array of products available for sale. Walk into your local drugstore and you’ll find chemical and mineral formulas in virtually every SPF count and format imaginable, from creams to sprays to sticks.

So which one should you throw in your beach bag this summer? Here’s how to choose the right sunscreen , according to dermatologists.

What’s the difference between chemical and mineral sunscreens?

There are two major types of sunscreen: chemical and mineral (also known as physical) formulas. They serve the same purpose—preventing sunburns and other skin damage from the sun’s UV radiation—but they do so in different ways.

Sunscreens made from the minerals titanium dioxide and zinc oxide create a physical barrier atop the skin that reflects UV light. Chemical sunscreens, meanwhile, feature active ingredients that sink into the skin and absorb UV rays “like a sponge,” explains Dr. Raman Madan, chief of dermatology at Glen Cove Hospital in New York. In the U.S., these include chemicals such as homosalate, oxybenzone, avobenzone, octinoxate, octisalate, and octocrylene.

Is chemical or mineral sunscreen better?

Many people prefer chemical formulas because they sink into the skin well, whereas mineral sunscreens can leave a chalky white residue. But that residue is a visible signal of these products’ staying power; mineral formulas tend to last longer than chemical sunscreens, says Dr. Abel Torres, chair of the University of Florida College of Medicine’s dermatology department. “If you know you’re going to be on the beach for a long time, mineral may be a better choice because you won’t have to worry about having to reapply it as much,” he says.

People with acne-prone skin may also benefit from a mineral sunscreen, since research suggests zinc can help clear blemishes , Torres notes. Those with sensitive skin may also do better with a mineral formula, Madan says, because—unlike chemical sunscreens—these products don’t sink deep into the skin, so “it’s almost impossible to be allergic” to them.

For the same reason, people who are skittish about product safety may want a mineral formula. Recent research shows that ingredients used in chemical sunscreens enter the bloodstream after soaking into the skin, and other studies (some conducted in animals) suggest sunscreen chemicals like oxybenzone may be linked to hormone disruption and increased risks of certain cancers . It’s too soon to say exactly if or how absorption of these chemicals affects health, Madan says, but people who are concerned may find peace of mind in mineral formulas.

Read More : Backward Walking Is the Best Workout You’re Not Doing

There’s broad support for that idea. The U.S. Food and Drug Administration (FDA) has said titanium dioxide and zinc oxide can be generally considered safe and effective , but that there’s not enough data to say the same for chemicals used in sunscreens . (The agency has asked manufacturers to submit additional safety information for analysis.) And all 83 sunscreens verified by the Environmental Working Group, a nonprofit that performs independent analysis of sunscreen safety, are mineral formulas.

Still, Torres emphasizes that studies have not proven that chemical formulas are dangerous; they’ve only hinted at potential risks. And there are plenty of known benefits to wearing sunscreen, whether chemical or mineral—most importantly, reducing the risk of skin cancer. So if chemical formulas are the ones you’ll actually use, it’s better to choose those than to go out unprotected.

Which SPF is best?

Sun protection factor, or SPF, is a measure of how much UV radiation it will take to burn your skin while wearing sunscreen versus while going without. The higher the SPF, the more robust the protection.

The FDA recommends choosing a product with an SPF of at least 15 , and the American Academy of Dermatology says it’s better to shoot for an SPF of 30 or above . People with fair skin may want to go even higher than that, Madan says—but after a certain point, SPF values offer diminishing returns. An SPF-50 formula offers such strong protection that upgrading to, say, SPF 100 offers only a tiny amount of additional benefit, he says.

Read More : The Unsettled—and Unsettling—Science of Lawn Chemicals

Just remember that regardless of which SPF you choose, you should reapply after a couple hours in the sun, especially if you’re swimming or sweating heavily. And, in addition to checking the SPF value, the Skin Cancer Foundation recommends choosing a sunscreen that is labeled with the phrase “broad-spectrum protection,” which means it protects against both UVA and UVB rays. UVA rays are responsible for wrinkles and skin aging, while UVB rays are the main cause of sunburns—but both are associated with skin cancer.

Is sunscreen best as a spray, lotion, or stick?

Sprays, sticks, and other formats are convenient, but Madan recommends a good old-fashioned cream if you have the choice. “It goes onto the skin a little bit thicker, so patients get more coverage out of a lotion,” he says. 

Research backs up that point. Studies have shown that people often don’t apply enough sunscreen when they use aerosol products, since the spray can be easily carried away by the wind and many formulas are diluted by propellants and other ingredients . Using a spray also introduces the possibility of inhaling potentially harmful substances , particularly if applied directly to the face.

But something is always better than nothing, Madan says—so if a spray is all you have, use that. The one exception? The FDA has said it needs more data to prove that sunscreen powder is effective, so Madan typically recommends patients steer clear of those products in favor of tried-and-true formulations.

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Here's What SPF You Need in Your Sunscreen, According to a Dermatologist

Is higher SPF actually better? And are you wearing enough? A skin doctor weighs in.

• Added coconut oil to cheap coffee before keto made it cool.

You've heard it before, and you've definitely read it here at CNET: Wear your sunscreen , or risk exposing yourself to harmful UV rays. 

But what SPF should you use? SPF , or sun protection factor, describes the amount of solar energy needed to produce a sunburn on protected skin relative to unprotected skin, according to the US Food and Drug Administration. Logic would follow, then, that wearing a higher SPF would offer you better protection when you're out and about, basking in the sun's rays. 

But is higher SPF sunscreen more protective in a measurable way that actually matters? The tested difference between SPF 30 and SPF 50 is small, according to Dr. Steven Daveluy, board-certified dermatologist and program director at Wayne State University Department of Dermatology -- a difference of 96.7% blocking vs. 98% blocking, in one example he gave. But research on people wearing sunscreen out in "real life" has suggested higher SPFs are more protective, Daveluy said in an email.

Combine this with the fact you're probably not wearing enough sunscreen -- studies have shown people apply only 25 to 50% of the amount that they should, Daveluy said -- and a higher SPF may come out reasonably more protective. 

"You should use about 1 ounce of sunscreen to cover your head, neck, arms, and legs when wearing shorts and a T-shirt," Daveluy recommended, adding that people without hair should use a little more. 

"That means your 3-ounce tube of sunscreen is only three applications," Daveluy said. "Most people are not using that amount."

How much SPF do you need in a sunscreen?

The American Academy of Dermatology Association recommends your sunscreen be SPF 30 or higher. It also recommends you look for sunscreen that has broad-spectrum protection (it protects against UVA and UVB rays) and make sure it's water-resistant. 

"If you follow the recommendations for the proper amount of sunscreen, then SPF 30 is great," Daveluy said. If you think you're skimping on the layers, though, a higher SPF could offer more benefit. He added that he generally recommends looking for at least SPF 50 or 60. 

Read more:   Don't Sweat It: These Clothes Can Help You Stay Cool Amid High Temperatures  

Does skin tone matter when choosing an SPF? 

People with darker skin tones have more melanin, which does offer some protection from the sun's damaging rays. For this reason, skin cancer rates in people of color are lower than rates in white people, but the risk isn't zero. Research also suggests that people of color may be more likely to experience a missed or late diagnosis of skin cancer , making outcomes more dangerous. (It's also important to note that melanoma can have other causes besides exposure to sunlight or UV rays, and can show up in areas not typically exposed to sun.)

"SPF 30 is the minimum for everyone," Daveluy said. He added that tinted sunscreens may be a better fit for darker skin tones, leaving less of a white cast. 

"If you have very fair skin, the higher [SPF] numbers may be a good idea, especially if you aren't using the proper amount, because you will see the consequences of underuse more easily," Daveluy said. 

Are there any sunscreen or SPF 'red flags'?

As long as you're wearing a minimum of SPF 30, applying it properly, and also looking for products that are broad spectrum and water resistant, you've got the basics down. Daveluy added that for people with sensitive skin, finding a mineral sunscreen with "active ingredients of zinc and/or titanium" may be a good choice.

Daveluy pointed out other measures of protecting yourself from the sun, including wearing a wide-brimmed hat, sun-protective clothing and hanging out in the shade when possible. But don't forget that sunscreen has a proven safety record going on decades, he said.

"The biggest red flags for sunscreen are any people or reports that try to tell you sunscreen isn't safe," Daveluy said. 

Read more: Are You Applying Enough Sunscreen?  

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What's keeping the US from allowing better sunscreens?

by Michael Scaturro, KFF Health News

When dermatologist Adewole "Ade" Adamson sees people spritzing sunscreen as if it's cologne at the pool where he lives in Austin, Texas, he wants to intervene. "My wife says I shouldn't," he said, "even though most people rarely use enough sunscreen."

At issue is not just whether people are using enough sunscreen , but what ingredients are in it.

The Food and Drug Administration's ability to approve the chemical filters in sunscreens that are sold in countries such as Japan, South Korea, and France is hamstrung by a 1938 U.S. law that requires sunscreens to be tested on animals and classified as drugs, rather than as cosmetics as they are in much of the world. So Americans are not likely to get those better sunscreens—which block the ultraviolet rays that can cause skin cancer and lead to wrinkles—in time for this summer, or even the next.

Sunscreen makers say that requirement is unfair because companies including BASF Corp. and L'Oréal, which make the newer sunscreen chemicals, submitted safety data on sunscreen chemicals to the European Union authorities some 20 years ago.

Steven Goldberg, a retired vice president of BASF, said companies are wary of the FDA process because of the cost and their fear that additional animal testing could ignite a consumer backlash in the European Union, which bans animal testing of cosmetics, including sunscreen. The companies are asking Congress to change the testing requirements before they take steps to enter the U.S. marketplace.

In a rare example of bipartisanship last summer, Sen. Mike Lee, R-Utah, thanked Rep. Alexandria Ocasio-Cortez (D-N.Y.) for urging the FDA to speed up approvals of new, more effective sunscreen ingredients. Now a bipartisan bill is pending in the House that would require the FDA to allow non-animal testing.

"It goes back to sunscreens being classified as over-the-counter drugs," said Carl D'Ruiz, a senior manager at DSM-Firmenich, a Switzerland-based maker of sunscreen chemicals. "It's really about giving the U.S. consumer something that the rest of the world has. People aren't dying from using sunscreen. They're dying from melanoma."

Every hour, at least two people die of skin cancer in the United States. Skin cancer is the most common cancer in America, and 6.1 million adults are treated each year for basal cell and squamous cell carcinomas, according to the Centers for Disease Control and Prevention. The nation's second-most-common cancer, breast cancer, is diagnosed about 300,000 times annually, though it is far more deadly.

Dermatologists offer tips on keeping skin safe and healthy:

• Stay in the shade during peak sunlight hours, 10 a.m. to 4 p.m. daylight time.
• Wear hats and sunglasses.
• Use UV-blocking sun umbrellas and clothing.
• Reapply sunscreen every two hours.

You can order overseas versions of sunscreens from online pharmacies such as Cocooncenter in France. Keep in mind that the same brands may have different ingredients if sold in U.S. stores. But importing your sunscreen may not be affordable or practical. "The best sunscreen is the one that you will use over and over again," said Jane Yoo, a New York City dermatologist.

Though skin cancer treatment success rates are excellent, 1 in 5 Americans will develop skin cancer by age 70. The disease costs the health care system $8.9 billion a year, according to CDC researchers. One study found that the annual cost of treating skin cancer in the United States more than doubled from 2002 to 2011, while the average annual cost for all other cancers increased by just 25%. And unlike many other cancers, most forms of skin cancer can largely be prevented—by using sunscreens and taking other precautions.

But a heavy dose of misinformation has permeated the sunscreen debate, and some people question the safety of sunscreens sold in the United States, which they deride as "chemical" sunscreens. These sunscreen opponents prefer "physical" or "mineral" sunscreens, such as zinc oxide, even though all sunscreen ingredients are chemicals.

"It's an artificial categorization," said E. Dennis Bashaw, a retired FDA official who ran the agency's clinical pharmacology division that studies sunscreens.

Still, such concerns were partly fed by the FDA itself after it published a study that said some sunscreen ingredients had been found in trace amounts in human bloodstreams. When the FDA said in 2019, and then again two years later, that older sunscreen ingredients needed to be studied more to see if they were safe, sunscreen opponents saw an opening, said Nadim Shaath, president of Alpha Research & Development, which imports chemicals used in cosmetics.

"That's why we have extreme groups and people who aren't well informed thinking that something penetrating the skin is the end of the world," Shaath said. "Anything you put on your skin or eat is absorbed."

Adamson, the Austin dermatologist, said some sunscreen ingredients have been used for 30 years without any population-level evidence that they have harmed anyone. "The issue for me isn't the safety of the sunscreens we have," he said. "It's that some of the chemical sunscreens aren't as broad spectrum as they could be, meaning they do not block UVA as well. This could be alleviated by the FDA allowing new ingredients."

Ultraviolet radiation falls between X-rays and visible light on the electromagnetic spectrum. Most of the UV rays that people come in contact with are UVA rays that can penetrate the middle layer of the skin and that cause up to 90% of skin aging, along with a smaller amount of UVB rays that are responsible for sunburns.

The sun protection factor, or SPF, rating on American sunscreen bottles denotes only a sunscreen's ability to block UVB rays. Although American sunscreens labeled " broad spectrum " should, in theory, block UVA light, some studies have shown they fail to meet the European Union's higher UVA-blocking standards.

"It looks like a number of these newer chemicals have a better safety profile in addition to better UVA protection," said David Andrews, deputy director of Environmental Working Group, a nonprofit that researches the ingredients in consumer products. "We have asked the FDA to consider allowing market access."

The FDA defends its review process and its call for tests of the sunscreens sold in American stores as a way to ensure the safety of products that many people use daily, rather than just a few times a year at the beach.

"Many Americans today rely on sunscreens as a key part of their skin cancer prevention strategy, which makes satisfactory evidence of both safety and effectiveness of these products critical for public health," Cherie Duvall-Jones, an FDA spokesperson, wrote in an email.

D'Ruiz's company, DSM-Firmenich, is the only one currently seeking to have a new over-the-counter sunscreen ingredient approved in the United States. The company has spent the past 20 years trying to gain approval for bemotrizinol, a process D'Ruiz said has cost $18 million and has advanced fitfully, despite attempts by Congress in 2014 and 2020 to speed along applications for new UV filters.

Bemotrizinol is the bedrock ingredient in nearly all European and Asian sunscreens, including those by the South Korean brand Beauty of Joseon and Bioré, a Japanese brand.

D'Ruiz said bemotrizinol could secure FDA approval by the end of 2025. If it does, he said, bemotrizinol would be the most vetted and safest sunscreen ingredient on the market, outperforming even the safety profiles of zinc oxide and titanium dioxide.

As Congress and the FDA debate, many Americans have taken to importing their own sunscreens from Asia or Europe, despite the risk of fake products.

"The sunscreen issue has gotten people to see that you can be unsafe if you're too slow," said Alex Tabarrok, a professor of economics at George Mason University. "The FDA is just incredibly slow. They've been looking at this now literally for 40 years. Congress has ordered them to do it, and they still haven't done it."

2024 Kaiser Health News. Visit khn.org. Distributed by Tribune Content Agency, LLC.

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• Skin Cancer

Here’s How Much Sunscreen You Actually Need on Your Face

By Jenna Ryu

If the dermatologists of TikTok and Instagram have taught us anything, it’s that sunscreen is one of the easiest and most effective ways to minimize UV damage. That includes wrinkles and dark spots , yes, but shielding your skin from the sun’s rays is also a must for preventing basal and squamous cell carcinoma (the most common forms of skin cancer ) and melanoma (the deadliest). Simply put, everyone’s daily skin care routine should include SPF. To get the most protection, though, you need to wear enough —especially on the most exposed parts of your body, like your face.

So how much sunscreen should you use on this extra vulnerable area, exactly? “Quantifying the exact amount can be really tough because everybody measures things differently,” Susan Massick, MD , a board-certified dermatologist at The Ohio State University Wexner Medical Center, tells SELF. In other words, most of us aren’t digging into our wallets to measure a “nickel-size” dollop of sunscreen every morning (the amount the Skin Cancer Foundation recommends for your face alone).

The problem with winging it: “A lot of folks don’t realize they’re not using enough,” Dr. Massick says. That’s why we’ve put together this visual guide: To help you figure out the perfect amount of SPF to cover your entire face (and neck).

So, how much sunscreen should you use on your face?

Dr. Massick has a couple of handy pointers: The first (and easiest to measure, in our opinion) is two finger lengths’ worth of sunscreen. Basically, that means spreading a thick line along your entire index and middle finger. You can also aim for a quarter-size blob. (See pictures below.)

“I’ve also seen a lot of people suggest a nickel-size dollop, but I don’t think that’s enough,” Dr. Massick says. “We want to make sure people are covering often-missed spots, too, like the ears, along the hairline, and behind and in front of the neck.”

Maybe you’re wondering if these rules apply to makeup with SPF too: The short answer is that you’ll likely still need a separate, dedicated sunscreen, because you probably aren’t wearing two fingers’ worth of foundation (since that can feel heavy), according to Dr. Massick. You also may not apply it evenly across your face, especially if you prefer more coverage in certain spots versus others. Plus, some makeup-sunscreen hybrids don’t offer “ broad-spectrum ” protection (against both UVA and UVB rays)—a must to stay safe.

“SPF in makeup is an added benefit, but it shouldn’t be used as the primary or only layer of defense,” Dr. Massick says—which is why she recommends a base of regular sunscreen, then a quarter-size dollop of the SPF makeup on top. But if that feels too goopy, it’s okay to use less, she adds—as long as you have that base coat of sunscreen underneath.

Do your lips need sunscreen too?

“The fact of the matter is that the lips are probably even more susceptible to sun damage ,” Dr. Massick says. Unlike the rest of your face, your lips don’t have as much melanin (pigment)—meaning “they don’t have that protective color to shield you from sun exposure,” she explains.

By Caroline Reilly

By Katie Camero

By Alice Oglethorpe

So you’ll want to be extra diligent about applying—and reapplying—sunscreen on that area, especially when you’re spending time outside. “You can swipe your regular sunscreen (with SPF 30, minimum) right across the lips,” Dr. Massick says. But if the texture feels weird, the formula isn’t moisturizing enough, or you simply prefer the convenience of a portable tube or stick, you can also use a lip balm with SPF . “Look for one with ingredients like hyaluronic acid and ceramides , which can hydrate and protect the skin barrier ,” Dr. Massick suggests.

One last friendly reminder: You should touch up your sunscreen every two hours—especially on your lips since SPF can easily be wiped or licked off throughout the day, she says. And if you’re not sure whether you’ve applied enough, go ahead and slather on a bit more, just to be safe. After all, it’s better to face the sun with too much SPF than not enough.

• I Was Tanning-Obsessed When I Was Younger…. Did I Doom Myself to Skin Cancer?
• 3 Things to Do If You’re Feeling Pressured to ‘Get in Shape’ for Summer
• Here’s How to Tell If Your Sunscreen Has Expired

SELF does not provide medical advice, diagnosis, or treatment. Any information published on this website or by this brand is not intended as a substitute for medical advice, and you should not take any action before consulting with a healthcare professional.

Have We Been Overdoing It On the Sunscreen?

By Kara McGrath

All products are independently selected by our editors. If you buy something, we may earn an affiliate commission.

It’s not even Memorial Day yet and I am exhausted by the sunscreen discourse. We’ve already had our annual bout of a celebrity declaring they’ve sworn off SPF , this time under the guidance of a self-proclaimed wellness guru who cites our ancestors' lack of Banana Boat as evidence that we don’t need the stuff. (As many have pointed out since, those ancestors were dying before the average onset age of skin cancer.) And this is coming on the heels of increasingly high-profile complaints that American sunscreen isn’t effective enough , with much of the blame falling to the FDA, which regulates the product as a drug with all the attendant red tape. (The FDA has not seen fit to approve a new sunscreen ingredient since 1999, leaving us far behind our sunscreen-consuming peers in Asia and Europe.)

The latest article to go viral in my more beauty-centric group chats is titled “ Against Sunscreen Absolutism .” Written by Rowan Jacobsen for The Atlantic , it centers largely around the Australian Skin and Skin Cancer Research Centre’s recently updated sun safety guidelines , which acknowledge two facts: 1. Australia has the highest incidence of skin cancer in the world (the majority of which can be attributed to UV exposure). 2. There are health benefits to exposing your skin to the sun (mostly with regard to vitamin D levels). The group’s final conclusion is a break from public health guidance in that it makes three different sets of sun protection recommendations based on an individual’s risk for skin cancer, rather than one sweeping directive for the entire population. (Those with dark skin, for example, are advised that they only need to wear sunscreen when they will be out in the bright sun for an extended period.) Jacobsen notes that the National Health Service in the UK appears on the brink of making similar guidance, but that a spokesperson for the American Academy of Dermatology (AAD) told him simply that the organization cannot recommend getting vitamin D from sun exposure because of the risk for skin cancer.

After more than a decade editing skin-care content, I recognize that the world of beauty journalism can be a bit pushy in its sunscreen evangelism. I recently received a draft of a to-be-published Allure story about sun protection that suggested we should be wearing (and reapplying!) full body sunscreen all day, every day, even in the middle of winter when you have no plans to leave the house. That, I’m sorry, is absurd—but it’s in line with what we’ve heard time and time again from dermatologists who no doubt have seen patients take the inch they’re given and run a mile in the blazing midday sun.

After more than three decades of living as a person in the United States, I also have come to the conclusion that we simply do not do nuance over here. I have loved ones who tell me they never have and never will wear sunscreen, citing concerns over putting “chemicals” on their skin. (They are not, however, opposed to the “chemicals” in the injectable anesthetics they’ve received when having multiple basal cell carcinomas sliced from their bodies.) I fear that any public policy change that acknowledges some sun exposure can have positive health benefits will only empower sunscreen skeptics to turn up their noses, putting them at risk for a disease that will at best require a surgical procedure and at worst kill them. “We know that 90% of skin cancers come from daily unprotected UV exposure,” Mona A. Gohara , MD, a board-certified dermatologist and associate clinical professor of dermatology at the Yale School of Medicine, told me quite plainly when I reached out to her this morning as I sat down to write this story. The numbers on the health benefits of sun exposure remain less cut-and-dried.

Besides, to be clear, even those of us wearing sunscreen daily in keeping with the current guidelines, are getting sun exposure. There’s a reason that the FDA prohibited the use of the term “sunblock” 25 years ago (along with the terms “waterproof” and “all-day protection”). Sunscreen is essentially a filter, helping to minimize our skin’s exposure to the sun—it does not fully block anything. And Allure has reported in the past that, on average, most sunscreen wearers are applying about half of what they would need to get the SPF listed on the bottle. And are they then reapplying every two hours? (I know I’m not. Are you?)

The only way to ensure that nary a UV ray touches your skin when you venture outside would be to wear layers of both sunscreen and UPF clothing from head to toe, reapplying several teaspoons worth of sunscreen every two hours. Dr. Gohara estimates that, on a daily average, about 80% of her patients are wearing sunscreen; only half of those are reapplying every two hours. Maybe 20% wear sun protective clothing, she estimates. And these are people engaged enough in their skin health that they’re seeing a dermatologist (something that the vast majority of Americans do not do regularly, or in many cases ever).

So how many times do we need to have the sunscreen talk? Much to my dismay (sunscreen is, in my opinion, quite dull as far as beauty-adjacent topics go), the limit likely does not exist. Scientific understanding of how much the risks of sun exposure outweigh the benefits can, and should, keep changing as more research is done.

But, for now, I feel compelled to remind you amidst all this chatter about whether the imagined sunscreen lobby has gone too far: There is no medically-backed recommendation that we should toss our sunscreen stash altogether or burn our rash guards en masse. Even research that shows some UV exposure might be beneficial only recommends spending five to 30 unprotected minutes in the sun. (A chemical sunscreen takes 15 to 30 minutes to start working, so this just means applying sunscreen right before you walk out the door.)

We don’t need to be shaming people for walking to their mailbox without reapplying SPF, but we should feel good—obligated even—in offering up our spare sunscreen to the group on a beach day. As with most things in life, the answer likely lies not in extremes but in moderation, though we may never find a way to effectively communicate this widely. “It is a slippery slope,” Dr. Gohara says. “It is like saying it’s OK to smoke half a cigarette, but not the whole thing. UV light is a carcinogen any way you slice it.”

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Why Americans aren’t getting better sunscreens this summer

Misinformation has played a big part.

By Michael Scaturro / KFF Health News | Published May 12, 2024 12:00 PM EDT

This article was originally published on  KFF Health News .

When dermatologist  Adewole “Ade” Adamson  sees people spritzing sunscreen as if it’s cologne at the pool where he lives in Austin, Texas, he wants to intervene. “My wife says I shouldn’t,” he said, “even though most people rarely use enough sunscreen.”

At issue is not just whether people are using enough sunscreen, but what ingredients are in it.

The Food and Drug Administration’s ability to approve the chemical filters in sunscreens that are sold in countries such as Japan, South Korea, and France is hamstrung by a 1938 U.S. law that requires sunscreens to be tested on animals and classified as drugs, rather than as cosmetics as they are in much of the world. So Americans are not likely to get those better sunscreens—which  block the ultraviolet rays  that can cause skin cancer and lead to wrinkles—in time for this summer, or even the next.

Sunscreen makers say that requirement is unfair because companies including  BASF Corp.  and  L’Oréal , which make the newer sunscreen chemicals, submitted  safety data  on sunscreen chemicals to the  European Union authorities  some 20 years ago.

Steven Goldberg, a retired vice president of BASF, said companies are wary of the FDA process because of the cost and their fear that additional animal testing could ignite a  consumer backlash  in the European Union, which  bans animal testing  of cosmetics, including sunscreen. The companies are asking Congress to change the testing requirements before they take steps to enter the U.S. marketplace.

In a rare example of bipartisanship last summer, Sen. Mike Lee (R-Utah)  thanked Rep. Alexandria Ocasio-Cortez  (D-N.Y.) for urging the FDA to speed up approvals of new, more effective sunscreen ingredients. Now a bipartisan bill is pending in the House that would  require the FDA  to allow non-animal testing.

“It goes back to sunscreens being classified as over-the-counter drugs,” said Carl D’Ruiz, a senior manager at DSM-Firmenich, a Switzerland-based maker of sunscreen chemicals. “It’s really about giving the U.S. consumer something that the rest of the world has. People aren’t dying from using sunscreen. They’re dying from melanoma.”

Every hour, at least two people  die of skin cancer  in the United States. Skin cancer is the  most common cancer  in America, and 6.1 million adults are treated each year for basal cell and squamous cell carcinomas, according to the  Centers for Disease Control and Prevention . The nation’s second-most-common cancer, breast cancer, is diagnosed about  300,000 times annually , though it is far more deadly.

Though skin cancer treatment success rates are excellent, 1 in 5 Americans will develop skin cancer by age 70. The disease costs the health care system  $8.9 billion a year , according to CDC researchers. One study found that the annual cost of treating skin cancer in the United States  more than doubled  from 2002 to 2011, while the average annual cost for all other cancers increased by just 25%. And unlike many other cancers, most forms of skin cancer can largely be prevented—by using sunscreens and taking other precautions.

But a heavy dose of misinformation has permeated the sunscreen debate, and some people question the safety of sunscreens sold in the United States, which they deride as “chemical” sunscreens. These sunscreen opponents prefer “physical” or “mineral” sunscreens, such as zinc oxide, even though all sunscreen ingredients are chemicals.

“It’s an artificial categorization,” said E. Dennis Bashaw, a retired FDA official who ran the agency’s clinical pharmacology division that studies sunscreens.

Still, such concerns were partly  fed by the FDA itself  after it published a study that said some sunscreen ingredients had been found in trace amounts in human bloodstreams. When the  FDA said in 2019 , and then again  two years later , that older sunscreen ingredients needed to be studied more to see if they were safe, sunscreen opponents saw an opening, said  Nadim Shaath , president of Alpha Research & Development, which imports chemicals used in cosmetics.

“That’s why we have extreme groups and people who aren’t well informed thinking that something penetrating the skin is the end of the world,” Shaath said. “Anything you put on your skin or eat is absorbed.”

Adamson, the Austin dermatologist, said some sunscreen ingredients have been used for 30 years without any population-level evidence that they have harmed anyone. “The issue for me isn’t the safety of the sunscreens we have,” he said. “It’s that some of the chemical sunscreens aren’t as broad spectrum as they could be, meaning they do not block UVA as well. This could be alleviated by the FDA allowing new ingredients.”

Ultraviolet radiation  falls between X-rays and visible light on the electromagnetic spectrum. Most of the UV rays that people come in contact with are UVA rays that can penetrate the middle layer of the skin and that cause up to 90% of skin aging, along with a smaller amount of UVB rays that are  responsible for sunburns .

The sun protection factor, or SPF, rating on American sunscreen bottles denotes only a sunscreen’s ability to block UVB rays. Although American sunscreens labeled “broad spectrum” should, in theory, block UVA light,  some studies have shown they fail  to meet the European Union’s higher UVA-blocking standards.

“It looks like a number of these newer chemicals have a better safety profile in addition to better UVA protection,” said  David Andrews , deputy director of Environmental Working Group, a nonprofit that researches the ingredients in consumer products. “We have asked the FDA to consider allowing market access.”

The FDA defends its review process and its call for tests of the sunscreens sold in American stores as a way to ensure the safety of products that many people use daily, rather than just a few times a year at the beach.

“Many Americans today rely on sunscreens as a key part of their skin cancer prevention strategy, which makes satisfactory evidence of both safety and effectiveness of these products critical for public health,” Cherie Duvall-Jones, an FDA spokesperson, wrote in an email.

D’Ruiz’s company, DSM-Firmenich, is the only one currently seeking to have a new over-the-counter sunscreen ingredient approved in the United States. The company has spent the past 20 years trying to gain  approval for bemotrizinol , a process D’Ruiz said has cost $18 million and has advanced fitfully, despite attempts by Congress in 2014 and 2020 to speed along applications for new UV filters.

Bemotrizinol is the bedrock ingredient in nearly all European and Asian sunscreens, including those by the South Korean brand  Beauty of Joseon  and  Bioré , a Japanese brand.

D’Ruiz said bemotrizinol could secure FDA approval by the end of 2025. If it does, he said, bemotrizinol would be the most vetted and safest sunscreen ingredient on the market, outperforming even the safety profiles of zinc oxide and titanium dioxide.

As Congress and the FDA debate, many Americans have taken to importing their own sunscreens from Asia or Europe, despite the  risk of fake products .

“The sunscreen issue has gotten people to see that you can be unsafe if you’re too slow,” said  Alex Tabarrok , a professor of economics at George Mason University. “The FDA is just incredibly slow. They’ve been looking at this now literally for 40 years. Congress has ordered them to do it, and they still haven’t done it.”

KFF Health News  is a national newsroom that produces in-depth journalism about health issues and is one of the core operating programs at KFF—an independent source of health policy research, polling, and journalism. Learn more about  KFF .

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Against Sunscreen Absolutism

Moderate sun exposure can be good for you. Why won’t American experts acknowledge that?

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A ustralia is a country of abundant sunshine, but the skin of most Australians is better adapted to gloomy England than the beaches of Brisbane. The country’s predominantly white population has by far the world’s highest rate of skin cancer , and for years the public-health establishment has warned residents about the dangers of ultraviolet light. A 1980s ad campaign advised Australians to “Slip, Slop, Slap”—if you had to go out in the sun, slip on a shirt, slop on some sunscreen, and slap on a hat. The only safe amount of sun was none at all.

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Then, in 2023, a consortium of Australian public-health groups did something surprising: It issued new advice that takes careful account, for the first time, of the sun’s positive contributions. The advice itself may not seem revolutionary—experts now say that people at the lowest risk of skin cancer should spend ample time outdoors—but the idea at its core marked a radical departure from decades of public-health messaging. “Completely avoiding sun exposure is not optimal for health,” read the groups’ position statement , which extensively cites a growing body of research. Yes, UV rays cause skin cancer, but for some, too much shade can be just as harmful as too much sun.

It’s long been known that sun exposure triggers vitamin D production in the skin, and that low levels of vitamin D are associated with increased rates of stroke, heart attack, diabetes, cancer, Alzheimer’s, depression, osteoporosis, and many other diseases. It was natural to assume that vitamin D was responsible for these outcomes. “Imagine a treatment that could build bones, strengthen the immune system and lower the risks of illnesses like diabetes, heart and kidney disease, high blood pressure and cancer,” The New York Times wrote in 2010 . “Some research suggests that such a wonder treatment already exists. It’s vitamin D.” By 2020, more than one in six adults were on that wonder treatment in the form of daily supplements, which promise to deliver the sun’s benefits without its dangers.

But sunlight in a pill has turned out to be a spectacular failure. In a large clinical trial that began in 2011, some 26,000 older adults were randomly assigned to receive either daily vitamin D pills or placebos, and were then followed for an average of five years. The study’s results were published in The New England Journal of Medicine two years ago. An accompanying editorial, with the headline “A Decisive Verdict on Vitamin D Supplementation,” noted that no benefits whatsoever had been found for any of the health conditions that the study tracked. “Vitamin D supplementation did not prevent cancer or cardiovascular disease, prevent falls, improve cognitive function, reduce atrial fibrillation, change body composition, reduce migraine frequency, improve stroke outcomes, decrease age-related macular degeneration, or reduce knee pain,” the journal said. “People should stop taking vitamin D supplements to prevent major diseases or extend life.”

Read: You’re not allowed to have the best sunscreens in the world

Australia’s new guidance is in part a recognition of this reality. It’s also the result of our improved understanding of the disparate mechanisms through which sunlight affects health. Some of them are intuitive: Bright morning light, filtered through the eyes, helps regulate our circadian rhythms, improving energy, mood, and sleep. But the systemic effects of UV light operate through entirely different pathways that have been less well understood by the public, and even many health professionals. In recent years, that science has received more attention, strengthening conviction in sunlight’s possibly irreplaceable benefits. In 2019, an international collection of researchers issued a call to arms with the headline “ Insufficient Sun Exposure Has Become a Real Public Health Problem .”

Health authorities in some countries have begun to follow Australia’s lead, or at least to explore doing so. In the United Kingdom, for example, the National Health Service is reviewing the evidence on sun exposure, with a report due this summer. Dermatology conferences in Europe have begun to schedule sessions on the benefits of sun exposure after not engaging with the topic for years.

In the United States, however, there is no sign of any such reconsideration. Both the CDC and the American Academy of Dermatology still counsel strict avoidance, recommending that everyone but infants wear sunscreen every day, regardless of the weather. When I asked the AAD about Australia’s new guidelines, a spokesperson offered only that, “because ultraviolet rays from the sun can cause skin cancer, the Academy does not recommend getting vitamin D from sun exposure.”

Such a stance surely reflects understandable concerns about mixed messaging. But it also seems more and more outdated, and suggests a broader problem within American public-health institutions.

More than a century ago, scientists began to notice a mysterious pattern across the globe, which they came to call the “latitude effect.” Once you adjust for confounding variables—such as income, exercise, and smoking rates—people living at high latitudes suffer from higher rates of many diseases than people living at low or middle latitudes. The pattern plays out in many conditions, but it’s most pronounced in autoimmune disorders, especially multiple sclerosis. Throughout Europe, Australia, New Zealand, and the U.S., populations at higher latitudes are much more likely to develop MS than those closer to the equator. Over the years, scientists have offered many theories to explain this phenomenon: differences in diet, something in the water. But MS research pointed to a perhaps more obvious answer: sunlight. The higher the latitude, the lower the angle of the sun and the more its rays are filtered by the atmosphere. A number of studies have found links between sun exposure and the disease. Kids who spend less than 30 minutes a day outside on weekends and holidays are much more likely to develop MS than kids who are outside for more than one hour on these same days. Relapse rates for the disease are higher in early spring, after months of sun scarcity. People who were born in the spring (whose mothers received little sun exposure during their third trimester of pregnancy) are more likely to develop MS than people born in the fall.

Here, too, scientists first assumed that vitamin D was the key. But vitamin D supplementation proved useless for MS. Could something else about sun exposure protect against the condition?

A hint came from another disease, psoriasis, a disorder in which the immune system mistakes the patient’s own skin cells for pathogens and attacks them, producing inflammation and red, scaly skin. Since ancient times, it had been observed that sunlight seems to alleviate the condition, and doctors have long recommended “phototherapy” as a treatment. But only in the late 20th century, with the recognition that psoriasis was an autoimmune disease, did they start to understand why it worked.

It turns out that UV light essentially induces the immune system to stop attacking the skin, reducing inflammation. This is unfortunate when it comes to skin cancer—UV rays not only damage DNA, spurring the formation of cancerous cells; they also retard the immune system’s attack on those cells. But in the case of psoriasis, the tamping-down of a hyperactive response is exactly what’s needed. Moreover, to the initial surprise of researchers, this effect isn’t limited to the site of exposure. From the skin, the immune system’s regulatory cells migrate throughout the body, soothing inflammation elsewhere as well.

Read: AI-driven dermatology could leave dark-skinned patients behind

This effect is now believed to be the reason sun exposure helps prevent or ameliorate many autoimmune diseases, including MS, type 1 diabetes, and rheumatoid arthritis. It also explains why other conditions that involve a hyperinflammatory response, such as asthma and allergies, seem to be alleviated by sun exposure. It may even explain why some other diseases now believed to be connected to chronic inflammation, including cardiovascular disease and Alzheimer’s, are often less prevalent in regions with more sun exposure.

The consortium of Australian public-health groups had those potential benefits in mind when it drafted its new guidelines. “There’s no doubt at all that UV hitting the skin has immune effects,” Rachel Neale, a cancer researcher and the lead author of the guidelines, told me. “There’s absolutely no doubt.” But as to what to do with that knowledge, Neale isn’t certain. “This is likely to be both harmful and beneficial. We need to know more about that balance.”

What does one do with that uncertainty? The original “Slip, Slop, Slap” campaign was easy to implement because of its simplicity: Stay out of the sun; that’s all you need to know. It was, in a sense, the equivalent of the “Just Say No” campaign against drugs , launched in the U.S. around the same time. But the simplicity also sometimes runs afoul of common sense. Dermatologists who tell their patients to wear sunscreen even indoors on cloudy winter days seem out of touch.

Australia’s new advice is, by comparison, more scientific, yet also more complicated. It divides its recommendations into three groups, according to people’s skin color and susceptibility to skin cancer. Those with pale skin, or olive skin plus other risk factors, are advised to practice extreme caution: Keep slip-slop-slapping. Those with “olive or pale-brown skin” can take a balanced approach to sun exposure, using sunscreen whenever the UV index is at least a 3 (which is most days of the year in Australia). Those with dark skin need sunscreen only for extended outings in the bright sun.

Read: The problem sunscreen poses for dark skin

In designing the new guidelines, Neale and her colleagues tried to be faithful to the science while also realizing that whatever line is set on sun exposure, many people will cross it, intentionally or not. Even though skin cancer is rarely fatal when promptly diagnosed, it weighs heavily on the nation’s health-care system and on people’s well-being. “We spend $2 billion a year treating skin cancer in Australia,” Neale said. “It’s bonkers how much we spend, apart from the fact that people end up with bits of themselves chopped out. So at a whole-population level, the messaging will continue to be very much about sun protection.”

That said, we now know that many individuals at low risk of skin cancer could benefit from more sun exposure—and that doctors are not yet prepared to prescribe it. A survey Neale conducted in 2020 showed that the majority of patients in Australia with vitamin D deficiencies were prescribed supplements by their doctors, despite the lack of efficacy, while only a minority were prescribed sun exposure. “We definitely need to be doing some education for doctors,” she told me. In support of the new position statement, Neale’s team has been working on a website where doctors can enter information about their patients’ location, skin color, and risk factors and receive a document with targeted advice. In most cases, people can meet their needs with just a few minutes of exposure a day.

That sort of customized approach is sorely needed in the United States, Adewole Adamson, a dermatologist who directs the Melanoma and Pigmented Lesion Clinic at the University of Texas, told me. “A one-size-fits-all approach isn’t productive when it comes to sun-exposure recommendations,” he said. “It can cause harm to some populations.” For years, Adamson has called for more rational guidelines for people of color, who have the lowest risk of skin cancer and also higher rates of many of the diseases that sunlight seems to ameliorate. Adamson finds it disheartening that mostly white Australia now has “a better official position” than organizations in the U.S., “where nonwhite Americans will outnumber white Americans in the next 20 years.”

To some degree, one can sympathize with the desire to keep things simple. People have limited bandwidth, and some may misunderstand or tune out overly complicated health messages. Others will inevitably turn a little information into a dangerous thing. A fringe segment of the alt-health crowd is already suggesting that skin-cancer dangers have been exaggerated as a way to get us all to buy more sunblock. But knowing that some people will draw strange conclusions from the facts is not a good-enough reason to withhold those facts, as we saw during the pandemic, when experts looking to provide simple guidance sometimes implied that the science was more settled than it was. This is not the 1950s. When public authorities spin or simplify science in an attempt to elicit a desired behavior, they are going to get called on it. Conspiracy-minded conclusions, among other bad ones, are likely to gain more credence, not less. And the public is going to have less faith in national institutions and the positions they espouse the next time.

Besides, in this case, the news being withheld is incredibly good. It’s not every day that science discovers a free and readily accessible intervention that might improve the health of so many people. That’s the real story here, and it’s most compelling when conveyed honestly: Science feels its way forward, one hesitant step at a time, and backtracks almost as often. Eventually, that awkward but beautiful two-step leads us to better ground.

This article appears in the June 2024 print edition with the headline “Against Sunscreen Absolutism.”

What’s keeping the U.S. from allowing better sunscreens?

• Michael Scaturro, KFF Health News

When dermatologist Adewole “Ade” Adamson sees people spritzing sunscreen as if it’s cologne at the pool where he lives in Austin, Texas, he wants to intervene. “My wife says I shouldn’t,” he said, “even though most people rarely use enough sunscreen.”

At issue is not just whether people are using enough sunscreen, but what ingredients are in it.

The Food and Drug Administration’s ability to approve the chemical filters in sunscreens that are sold in countries such as Japan, South Korea, and France is hamstrung by a 1938 U.S. law that requires sunscreens to be tested on animals and classified as drugs, rather than as cosmetics as they are in much of the world. So Americans are not likely to get those better sunscreens — which block the ultraviolet rays that can cause skin cancer and lead to wrinkles — in time for this summer, or even the next.

Sunscreen makers say that requirement is unfair because companies including BASF Corp. and L’Oréal , which make the newer sunscreen chemicals, submitted safety data on sunscreen chemicals to the European Union authorities some 20 years ago.

Steven Goldberg, a retired vice president of BASF, said companies are wary of the FDA process because of the cost and their fear that additional animal testing could ignite a consumer backlash in the European Union, which bans animal testing of cosmetics, including sunscreen. The companies are asking Congress to change the testing requirements before they take steps to enter the U.S. marketplace.

In a rare example of bipartisanship last summer, Sen. Mike Lee, R-Utah, thanked Rep. Alexandria Ocasio-Cortez (D-N.Y.) for urging the FDA to speed up approvals of new, more effective sunscreen ingredients. Now a bipartisan bill is pending in the House that would require the FDA to allow non-animal testing.

“It goes back to sunscreens being classified as over-the-counter drugs,” said Carl D’Ruiz, a senior manager at DSM-Firmenich, a Switzerland-based maker of sunscreen chemicals. “It’s really about giving the U.S. consumer something that the rest of the world has. People aren’t dying from using sunscreen. They’re dying from melanoma.”

Every hour, at least two people die of skin cancer in the United States. Skin cancer is the most common cancer in America, and 6.1 million adults are treated each year for basal cell and squamous cell carcinomas, according to the Centers for Disease Control and Prevention . The nation’s second-most-common cancer, breast cancer, is diagnosed about 300,000 times annually , though it is far more deadly.

Dermatologists Offer Tips on Keeping Skin Safe and Healthy

– Stay in the shade during peak sunlight hours, 10 a.m. to 4 p.m. daylight time.– Wear hats and sunglasses. – Use UV-blocking sun umbrellas and clothing. – Reapply sunscreen every two hours.You can order overseas versions of sunscreens from online pharmacies such as Cocooncenter in France. Keep in mind that the same brands may have different ingredients if sold in U.S. stores. But importing your sunscreen may not be affordable or practical. “The best sunscreen is the one that you will use over and over again,” said Jane Yoo , a New York City dermatologist.

Though skin cancer treatment success rates are excellent, 1 in 5 Americans will develop skin cancer by age 70. The disease costs the health care system $8.9 billion a year , according to CDC researchers. One study found that the annual cost of treating skin cancer in the United States more than doubled from 2002 to 2011, while the average annual cost for all other cancers increased by just 25%. And unlike many other cancers, most forms of skin cancer can largely be prevented — by using sunscreens and taking other precautions.

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But a heavy dose of misinformation has permeated the sunscreen debate, and some people question the safety of sunscreens sold in the United States, which they deride as “chemical” sunscreens. These sunscreen opponents prefer “physical” or “mineral” sunscreens, such as zinc oxide, even though all sunscreen ingredients are chemicals.

“It’s an artificial categorization,” said E. Dennis Bashaw, a retired FDA official who ran the agency’s clinical pharmacology division that studies sunscreens.

Still, such concerns were partly fed by the FDA itself after it published a study that said some sunscreen ingredients had been found in trace amounts in human bloodstreams. When the FDA said in 2019 , and then again two years later , that older sunscreen ingredients needed to be studied more to see if they were safe, sunscreen opponents saw an opening, said Nadim Shaath , president of Alpha Research & Development, which imports chemicals used in cosmetics.

“That’s why we have extreme groups and people who aren’t well informed thinking that something penetrating the skin is the end of the world,” Shaath said. “Anything you put on your skin or eat is absorbed.”

Adamson, the Austin dermatologist, said some sunscreen ingredients have been used for 30 years without any population-level evidence that they have harmed anyone. “The issue for me isn’t the safety of the sunscreens we have,” he said. “It’s that some of the chemical sunscreens aren’t as broad spectrum as they could be, meaning they do not block UVA as well. This could be alleviated by the FDA allowing new ingredients.”

Ultraviolet radiation falls between X-rays and visible light on the electromagnetic spectrum. Most of the UV rays that people come in contact with are UVA rays that can penetrate the middle layer of the skin and that cause up to 90% of skin aging, along with a smaller amount of UVB rays that are responsible for sunburns .

The sun protection factor, or SPF, rating on American sunscreen bottles denotes only a sunscreen’s ability to block UVB rays. Although American sunscreens labeled “broad spectrum” should, in theory, block UVA light, some studies have shown they fail to meet the European Union’s higher UVA-blocking standards.

“It looks like a number of these newer chemicals have a better safety profile in addition to better UVA protection,” said David Andrews , deputy director of Environmental Working Group, a nonprofit that researches the ingredients in consumer products. “We have asked the FDA to consider allowing market access.”

The FDA defends its review process and its call for tests of the sunscreens sold in American stores as a way to ensure the safety of products that many people use daily, rather than just a few times a year at the beach.

“Many Americans today rely on sunscreens as a key part of their skin cancer prevention strategy, which makes satisfactory evidence of both safety and effectiveness of these products critical for public health,” Cherie Duvall-Jones, an FDA spokesperson, wrote in an email.

D’Ruiz’s company, DSM-Firmenich, is the only one currently seeking to have a new over-the-counter sunscreen ingredient approved in the United States. The company has spent the past 20 years trying to gain approval for bemotrizinol , a process D’Ruiz said has cost $18 million and has advanced fitfully, despite attempts by Congress in 2014 and 2020 to speed along applications for new UV filters.

Bemotrizinol is the bedrock ingredient in nearly all European and Asian sunscreens, including those by the South Korean brand Beauty of Joseon and Bioré , a Japanese brand.

D’Ruiz said bemotrizinol could secure FDA approval by the end of 2025. If it does, he said, bemotrizinol would be the most vetted and safest sunscreen ingredient on the market, outperforming even the safety profiles of zinc oxide and titanium dioxide.

As Congress and the FDA debate, many Americans have taken to importing their own sunscreens from Asia or Europe, despite the risk of fake products .

“The sunscreen issue has gotten people to see that you can be unsafe if you’re too slow,” said Alex Tabarrok , a professor of economics at George Mason University. “The FDA is just incredibly slow. They’ve been looking at this now literally for 40 years. Congress has ordered them to do it, and they still haven’t done it.”

KFF Health News is a national newsroom that produces in-depth journalism about health issues and is one of the core operating programs of KFF — the independent source for health policy research, polling and journalism.

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• J Clin Aesthet Dermatol
• v.6(1); 2013 Jan

Sunscreening Agents

a Global Medical Affairs, Dr. Reddy's Laboratories Ltd., Hyderabad, India;

Jacintha Martis

b Department of Dermatology, Fr. Muller Medical College, Mangalore, India;

Rutuja Sham Shinde

c Department of Dermatology, Dr. Reddy's Laboratories Ltd., Hyderabad, India;

Sudhakar Bangera

d Clinical Research Consultant, Hyderabad, India;

Binny Krishnankutty

e Department of Pharmacology, Azeezia Medical College, Kollam, India

Shantala Bellary

Sunoj varughese, prabhakar rao, b.r. naveen kumar.

The increasing incidence of skin cancers and photodamaging effects caused by ultraviolet radiation has increased the use of sunscreening agents, which have shown beneficial effects in reducing the symptoms and reoccurrence of these problems. Many sunscreen compounds are in use, but their safety and efficacy are still in question. Efficacy is measured through indices, such as sun protection factor, persistent pigment darkening protection factor, and COLIPA guidelines. The United States Food and Drug Administration and European Union have incorporated changes in their guidelines to help consumers select products based on their sun protection factor and protection against ultraviolet radiation, whereas the Indian regulatory agency has not yet issued any special guidance on sunscreening agents, as they are classified under cosmetics. In this article, the authors discuss the pharmacological actions of sunscreening agents as well as the available formulations, their benefits, possible health hazards, safety, challenges, and proper application technique. New technologies and scope for the development of sunscreening agents are also discussed as well as the role of the physician in patient education about the use of these agents.

Photoprotective agents protect the skin by preventing and minimizing the damaging effects of ultraviolet (UV) rays of natural light. They can be used as sunblock, which is opaque when applied over the skin and blocks a higher percentage of light as compared to sunscreens, which are translucent and require frequent reapplication for optimum efficacy. Photoaging—manifested as sagging, wrinkling, and photocarcinogenesis—is caused by damage to cells and deoxyribonucleic acid (DNA). It has been observed that sunscreens increase skin's tolerability to UV rays. 1

UV radiation has broad spectrum, ranging from 40 to 400nm (30–3eV), which is divided into Vacuum UV (40–190nm), Far UV (190–220nm), UVC (220–290nm), UVB (290–320), and UVA (320–400nm), of which the latter two are medically important. There are two distinct subtypes of UVA radiation. Short-wave UVA (320–340nm) and long-wave UVA (340–400nm), the latter constituting most of UVA radiation. The amount of exposure to UVA usually remains constant, whereas UVB exposure occurs more in the summer. 2

Effects of UVA manifest usually after a long duration of exposure, even if doses are low. It has been postulated that UVA up regulates the formation of matrix metalloproteinase (MMPs), enzymes that degrade the matrix protein's elastin and collagen, which, if not prevented, can result in marked reduction in skin elasticity and increased wrinkling. UVA radiation damages skin by penetrating into the layers of skin and producing reactive oxygen resulting in acute and chronic changes. 2 UVA radiation can induce polymorphous light eruptions (PMLE) in sensitive skin, 3 but in some it has also shown to reduce PMLE. 4 UVA can also cause exacerbation of cutaneous lupus erythematoses, whereas solar urticaria can be caused by both UVA and UVB radiation. 5

Studies have shown that UVA impairs the antigen presenting cell (APC) activity of the epidermal cells and thereby causes immune suppression, thus contributing to the growth of skin cancer. Sunscreening agents have shown to provide significant protection against epidermal APC activity induced by high UVA dose. 6 Mutation occurring in human melanocyte due to damage caused to DNA by UVA radiation is one of the proposed reasons. 7 In summary, UVA radiation can cause nuclear and mitochondrial DNA damage, gene mutations and skin cancer, dysregulation of enzymatic chain reactions, immune suppression, lipid peroxidation (membrane damage), and photoallergic and phototoxic effects.

UVB radiation can also cause acute changes, such as pigmentation and sunburn, and chronic changes, such as immune-suppression and photocarcinogenesis. Both UVA and UVB radiation can cause sunburn, photoaging reactions, erythema, and inflammation. 2

Sunburn is the most commonly encountered skin damage caused by natural light. Improper sunscreen usage and inadequate application also contribute to the increased prevalence of sunburn, despite the frequent use of sunscreening agents. Available evidence indicates that sunburn is more commonly seen in white-skinned people and young people with sensitive skin. Sunburn is common in the United States with 34.4 percent of adults affected. 8 In Sweden, children are frequently affected, and use of sunscreen among children has been found to be protective. 9

With the increased incidence in skin cancer cases, such as squamous and basal cell carcinomas, reported worldwide, use of photoprotective agents has increased over the years. 10 , 11 There has been symptomatic improvement and inhibition of reoccurrence of these conditions when photoprotective agents are used either therapeutically or prophylactically, indicating the need to promote and regularize their application.

The authors intend to spread awareness among physicians regarding the amount of sunscreening agents needed, method of application, reapplication, and the importance of patient education in all populations in order to reduce the damaging solar effects on skin.

Composition and Mechanism of Action

Sunscreening agents contain titanium dioxide (TiO 2 ), kaolin, talc, zinc oxide (ZnO), calcium carbonate, and magnesium oxide. Newer chemical compounds, such as bemotrizinol, avobenzone, bisoctizole, benzophenone-3 (BZ-3, oxybenzone), and octocrylene, are broad-spectrum agents and are effective against a broad range of solar spectrum both in experimental models and outdoor settings. Ecamsule (terephthalylidene dicamphor sulphonic acid), dometrizole trisiloxane, bemotrizinol, and bisoctrizole are considered organic UVA sunscreening agents. Classification 12 of sunscreening agents is shown in Figure 1 . Commercial preparations available in the market include a combination of these agents to cover a wide range of UV rays.

Classification of sunscreening agents

Composition and mechanism of action of sunscreening agents vary from exerting their action through blocking, reflecting, and scattering sunlight. Chemical sunscreens absorb high-energy UV rays, and physical blockers reflect or scatter light. Multiple organic compounds are usually incorporated into chemical sunscreening agents to achieve protection against a range of the UV spectrum. Inorganic particulates may scatter the microparticles in the upper layers of skin, thereby increasing the optical pathway of photons, leading to absorption of more photons and enhancing the sun protection factor (SPF), resulting in high efficiency of the compound. 13 , 14

Researchers are postulating that the generation of sunlight-induced free radicals causes changes in skin; use of sunscreens reduces these free radicals on the skin, suggesting the antioxidant property. 15 Broad-spectrum agents have been found to prevent UVA radiation-induced gene expression in vitro in reconstructed skin and in human skin in vivo . 16

Insect repellents, such as picaridin and N, N-diethyl-3-methylbenzamide (DEET), have been incorporated into sunscreening agents to minimize the risk of developing insect-borne infections. Picardin was found to be a more suitable component than DEET when used along with BZ-3, as it minimizes the penetration of chemicals. 17

Ideal sunscreening agents should be safe, chemically inert, nonirritating, nontoxic, photostable, and able to provide complete protection to the skin against damage from solar radiation. They should be formulated in a cosmetically acceptable form and ingredients should remain on the upper layers of the skin even after sweating and swimming. Sunscreening agents should provide efficient scavenging activities against singlet oxygen and other reactive oxygen species. 18 They should also effectively block both UVB and UVA rays, which is possible with an agent that has an SPF of 30 or greater. Sunscreens with an SPF of 30 or greater that incorporate photostable or photostabilized UVA filters (labeled as “broad spectrum” in the US) are usually ideal. 19 Sunscreens should not only protect the skin from the sun, but also minimize the cumulative health hazards from sun damage caused over time.

Factors Determining Efficacy

SPF and substantivity (the property of continuing therapeutic action despite removal of the vehicle ) are the factors that contribute to the effectiveness of sunscreening agents. 20 UVB protection is measured by a product's SPF, which theoretically indicates that products with high SPFs provide more protection against hazardous effects of sunlight than those with low SPFs. 21 SPF is measured as the ratio of the amount of UV radiation required to burn the protected skin (with sunscreen) to that required to burn the same unprotected skin (without sunscreen), all other factors being constant. SPF is measured using the following formula:

SPF = MED of protected skin/MED of unprotected skin (MED = minimal erythemal dose) .

This means when a product with SPF 50 is applied, it will protect the skin until it is exposed to 50 times more UVB radiation than that is required to burn the unprotected skin.

SPF level, efficacy against a wavelength of UV radiation, and UVA/UVB ratio can be calculated using a computer program or software, such as sunscreen simulators, and can determine if the product meets the regulatory standards.

Bodekaer et al 22 studied the reduction in SPF of organic and inorganic sunscreening agents in participants who, over the course of eight hours, performed physical activities, were then exposed to a hot environment, and finally bathed. There was a reduction in SPF of 38 and 41 percent after four hours and of 55 and 58 percent after eight hours of application of organic and inorganic sunscreen, respectively. 22 Hence, it is necessary to apply the adequate and recommended amount of sunscreening agent to obtain the claimed benefit (i.e., 2mg/cm 2 , which is shown to be effective on Asian skin as well). Studies have shown that people apply about a quarter of the recommended dose of sunscreen, which is an inadequate amount. 23 , 24

Protection offered by a sunscreening agent against UVA radiation is measured by the Persistent Pigment Darkening (PPD) Protection Factor. This technique was developed in Japan and has been routinely used by manufacturers. Stanfield 25 has discussed its disadvantages. PPD is not done in skin type 1, which is the skin type more prone to solar damage. For wavelengths less than 320nm, action sprectrum is not defined; moreover, clinical significance of PPD is not very clear.

Immediate pigment darkening response is calculated as the dose of UVA required to produce the effect with the sunsceening agent to that produced without an agent. 26 Although this test gives rapid results for low doses of UVA, responses have been found to be highly variable and an accurate reproduction of results is difficult. This is usually performed in skin types III and IV and its clinical significance is unknown. 27

COLIPA guideline is a new standardized, reproducible, and in-vitro method to measure UVA protection offered by sunscreening products and was developed by “ In-Vitro Sun Protection Methods” group. This has been in use by European Union (EU) countries for testing and labeling sunscreen products as it is in line with regulatory recommendation. 28

Immunoprotection factor is a measure of a sunscreening agent to prevent UV-induced immunosuppression. 12

Regulatory Guidelines

Misguiding information on sunscreen labels has compelled regulatory agencies to make changes in the international regulatory guideline on sunscreens to avoid confusion among the general public, to assist them in selecting a suitable agent, to provide adequate sun protection, and to minimize health hazards of solar damage including the occurrence of skin cancers.

United States Food and Drug Administration (FDA) guidelines. Previously, FDA guidelines 29 , 30 aimed at protection against UVB radiation and sunburns, not toward protection against UVA radiation and prevention of skin cancers. Inappropriate and misguiding labeling with false claims has made the FDA revise its guidelines on sunscreening agents. New, improvised guidelines address such issues as “broad-spectrum designation, use claims, waterproof, sweat proof, sun proof, and water resistance claims and drug facts”. According to the new guidelines, claims about UVA and UVB protection should be made only after the specific tests have proved the same. It is mandatory to test both UVA and UVB radiation. A product can be classified as a broad-spectrum sunscreening agent if it passes the required test, but the reduction in the risk of skin cancer and early skin aging when used as per direction can be stated by only those with SPF 15 or higher. Those with SPF 2 to 14 cannot state the latter.

Labels claiming sunscreens are “waterproof,” “sweat proof,” or “sun blocks” are not legally permitted as these claims overemphasize the product's efficacy. If a product claims to be water resistant, the label should clearly indicate the duration of effectiveness (e.g., 40 minutes or 80 minutes) during activities such as swimming. If the product does not claim to be water resistant, consumers should be instructed to use a water-resistant sunscreen during swimming and those activities that produce sweat. Reapplication for better efficacy has to be mentioned on the label, and manufacturers are not allowed to claim sun protection lasting more than two hours without reapplication. Claims, such as instant protection, are also not permitted. If any such claims are made, supporting data should be submitted to obtain FDA approval.

Labels should also include standard drug facts. Products containing an SPF of more than 50 should mention in the label that there is a lack of evidence to support that sunscreens with an SPF of more than 50 have better efficacy than those containing SPF 50 or below. Manufacturers have to submit supporting data if the formulation is a spray or another dosage form of which comparison with the regular dosage form, such as cream or lotion, is not possible. These new rules became effective June 18, 2012.

EU guidelines. Revised EU guidelines 31 , 32 mandate a minimum level of UVA protection in terms of SPF. The UVA protection factor measured by PPD ( in vivo ) or COLIPA ( in vitro ) must be at least one-third of the SPF in-vivo value. Products with SPF 6, 10, 15, 20, 25, 30, 50, 50+ are permitted for consumer use and are categorized as low (SPF 6, 10), medium (SPF 15, 20, 25), high (SPF 30, 50), and very high (SPF 50+). Compounds should provide protection against a minimum critical wavelength of 37nm, which is also under consideration. Products that meet the regulatory standard will have the UVA seal.

Actual protection against UVA is represented by a star system for easy understanding by consumers. This measure was developed by Boots Company in Nottingham, United Kingdom, and was based on Diffey's UVA/UVB ratio. The star system ranges from one to five stars where 1=minimum sun protection, 2=moderate, 3=good, 4=superior, and 5=ultra.

Guidelines from other countries. Japan, Australia, and New Zealand have their own indices on UV protection factor. 12 Australian standards define UVA protection in a compound when the transmission of sunlight between a wavelength of 320 and 360nm (at a path length of 8µm) is less than 10% (of the incoming light that is passing through).

New Australian guidelines have set SPF 50+ as a benchmark for sunscreening agents. It has also endorsed the revisions by international standards on terminology, such as “water resistant,” “waterproof,” “sun block,” and “sweat resistant,” as these terms are misleading to consumers. High requirements have been set by the guideline regarding water resistance as per their lifestyle requirement. 33

Japanese regulatory guidelines 34 describe the method of testing the photoprotection factor of UVA (PFA) as the amount of product to be applied, dose of radiation, and radiation field. These guidelines define minimal persistent pigment darkening (MPPD) dose as the minimum dose of UV rays required to produce slight darkening over the whole radiation area within 2 to 4 hours after exposure. The guidelines also define the time to measure MPPD and who should measure it. PFA is calculated using the following formula:

PFA = MPPD of protected skin/MPPD of unprotected skin. Products are graded based on the PFA value ( Table 1 ) .

Photoprotection grades according to Japanese cosmetic industry association guidelines

Source: JCIA/persistent pigment darkening protocol

Korea follows Korean measurement standards for UV protection effects (KFDA) and has standards for UVB protection (SPF measurement) and protection grade of UVA (PA). On labels, SPF should be listed for UVB and PA for UVA. 35

India guidelines. In India, there are no industry guidelines for standardizing sunscreen agents and there is no detailed list of approved products. The Indian regulatory agency's official website lists only two combination products as approved drugs ( Table 2 ). Many products are classified as cosmetics and are not listed in this section. Apart from routinely used agents, such as BZ-3, ZNO, and TiO 2 , other agents, such as camphor benzalkonium methosulfate (6%), octyl salicylate (5%), camphor derivatives, and broad-spectrum UV filters (i.e., bis-ethylhexyloxyphenol mcthoxyphcnyl triazine [10%] and methylene bis-benzotriazolyl tetramethylbutylphenol [10%]) are widely used. Table 2 lists some of these agents, which are manufactured by pharmaceutical companies and are available in India. Most of the products available are combination products.

Approved sunscreeening agents (combination products) and available preparations in India

Pharmacokinetics

It was observed that lipid microparticles loaded with ethylhexyl methoxycinnamate (EHMC), which filters UVB, and butyl methoxydibenzoylmethane (BMDBM), which filters UVA, had reduced skin penetration, thus preserving the UV filter efficacy and limiting potential toxicological risks. 36 Gonzalez et al 37 studied the percutaneous absorption of BZ-3 after repeated whole-body applications, with and without UV irradiation in 25 volunteers. They observed that large amounts of BZ-3 is absorbed, accumulated in the body, and excreted, even after five days after the last application. 37 In another study, pharmacokinetics of BZ-3 was studied in 11 healthy volunteers after topical application. After 48 hours, the average amount of BZ-3 excreted in urine was 11mg (median=9.8mg). In some volunteers, BZ-3 was excreted even after 48 hours. This study showed that BZ-3 undergoes conjugation and converts to a water-soluble compound. The age at which liver attains maturity and is able to metabolize these chemicals and conjugate is unknown. Therefore, it is recommended that physical filters (i.e., zinc oxide, titanium dioxide, ferrous oxide) be used in children. 38 BZ-3 is FDA approved for use in children above six months of age.

Pharmacokinetics of the following three chemical UV absorbers—benzophenone-3 (BZ-3), octyl-methoxy-cinnamate (OMC), and 3-(4-methylbenzylidene) camphor (4-MBC)—were studied in 32 healthy volunteers, 15 of whom were young male volunteers and 17 of whom were postmenopausal women. The volunteers were exposed to daily whole-body topical application of 2mg/cm 2 of sunscreen formulation at 10% (weight/weight) for four days. Blood and urine concentrations were measured at regular intervals as specified in the protocol. Before the first application of these agents, their concentration was undetectable in plasma and urine, but was detectable 1 to 2 hours after the first application. In female volunteers, the maximum median plasma concentrations of 187ng/mL BP-3, 16ng/mL 4-MBC, and 7ng/mL OMC were seen. In male volunteers, maximum median plasma concentrations were 238ng/mL (BZ-3), 18ng/mL (4-MBC), and 16ng/mL OMC.

The urinary concentration level of BZ-3 was higher in men (81ng/mL) than women (44ng/mL). However, no significant changes were seen with other agents (female volunteers = 4ng/mL of 4-MBC and 6ng/mL OMC; male volunteers = 4ng/mL of 4-MBC and OMC). Men showed a higher concentration of 4-MBC and OMC, whereas women showed a similar pattern in BZ-3 and 4-MBC when 96-hour median concentrations were compared to 24-hour concentrations. 39

Janjua et al 40 studied the absorption of sunscreens BZ-3, octyl-methoxycinnamate (OMC), and 3-(4-methyl-benzylidene) camphor (4-MBC) from topical application and their effects on the endogenous reproductive hormones in 32 healthy volunteers. After two-week, whole-body application, there was no change in follicle-stimulating hormone (FSH) levels or luteinizing hormone (LH) levels, but there was a minor difference in testosterone levels. In men, a minor difference in serum estradiol and inhibin B levels were observed. 40

Formulation also plays a role in the penetration of the compound to the skin. Skin penetration of BZ-3 is faster and greater if formulated as emulsion. However, the rate of penetration is dependent on the concentration of BZ-3 in the formulation. 41

Filipe et al 42 studied the localization of TiO 2 and ZnO nanoparticles and their skin penetration levels and concluded that drug concentration was either undetectable or insufficient under the stratum corneum, indicating minimal systemic absorption with no or minimal penetration into keratinocytes and good skin retention. 42 – 44 Lacatusu et al 45 showed that coupling UV absorbers and lipid nanoparticles makes the combination photostable and provides better photoprotection. 45

Efficacy of a sunscreen is tested in vitro and in vivo for SPF, UVA indices, and UV protection profile. Figures 2 and ​ and3 3 show the SPF and UV indices for a product with SPF 30 and Figures 4 and ​ and5 5 show that for a compound with SPF 50. The ability of a sunscreen to absorb UV radiation is measured in terms of extinction coefficient value. Figure 6 shows the optimal UV protection across the full UV spectrum of various UV filters.

SPF profile of a product with SPF 30

UV protection profile of a product with SPF 30. Profiles before (initial) and after (final) irradiation dose of SPF × MED (1 Minimal Erythema Dose passes through sunscreen onto skin).

SPF profile of a product with SPF 50

UV protection profile of a product with SPF 50

Optimal UV protection across the full UV spectrum of various UV filters

Studies are suggesting the use of broad-spectrum sunscreening agents for greater protection. 46 Daily application of these agents helps in minimizing solar UV-induced skin changes. 47 Results of a study by Diffey 11 indicated that regular use of topical photoprotective agents significantly reduces lifetime UV exposure to the face compared to nonuse. The study also emphasized that it is very important to begin regular daily use of topical sunscreens early in life. Sunscreens are used more during the summer season than throughout the year in some regions. Consumers consider SPF, action of sunscreens against UV range, and the usage pattern as less important. 11 Green et al 48 observed reduction in the incidence of squamous cell carcinoma (40%) and basal cell carcinoma with regular use of sunscreens, supporting their role in the prevention of these skin cancers.

Kuhn et al 49 assessed the exclusive use of a broad-spectrum sunscreen in preventing the skin lesions in patients with different subtypes of cutaneous lupus erythematosus (CLE) induced by UV irradiation under standardized conditions in 25 patients. They concluded that use of broad-spectrum sunscreening agents prevents skin lesions in these patients. Efficacy of sunscreens depends upon skin type, amount and frequency of application, exposure to sunlight and time of day, environmental factors, and the amount of product absorbed by the skin.

The safety of sunscreening agents is determined by toxicity studies, ability to cause irritation, sensitization, phototoxicity, and its impact on environment. Hayden et al 50 studied the safety of five commonly used sunscreen agents (avobenzone, octinoxate, octocrylene, BZ-3 [oxybenzone] and padimate O) by determining the penetration of topical agents and found that BZ-3 penetrated the epidermis the most after 24 hours of exposure; however, the concentration in the stratum corneum was too low to cause toxicity. Toxicities have been reported with BZ-3, which has been associated with anaphylaxis. 51 The inhalation of spray sunscreens can pose a danger as well. McKinney et al observed pulmonary and cardiovascular changes in rats on inhalation of a product containing TiO 2 nanoparticles.

Use of sunscreening agents in Asian skin

Asian skin is classified as type IV, 26 which is darker in color, rarely burns, and is more prone to rapid tanning. Asian skin is comparatively smoother, with a slight yellowish tinge and is more prone to pigmentation. Presence of protein melanin in the skin of Asians differentiates it from the skin of Caucasians. It has been observed that melanin equally filters all wavelengths of light, thereby receiving five times less UV radiation. This protein provides photoprotection to a certain extent, minimizing phototoxicity and making the skin less vulnerable to the acute and chronic phototoxic effects. 52 Nevertheless, this population shows the effects of photodamage in terms of pigmentation, wrinkling, and sunburn. The formation of freckles in the Asian population is encountered much less frequently. However, overexposure to sunlight can cause photodamaging effects, including skin cancers. Hence, it is advisable for Asians to use sunscreening agents regularly as a preventive measure just as it is in other parts of the world. However, since Asian skin is more prone to hypersensitivity reactions, cosmetic products should be used with care.

Sunscreen Use in Special Populations

Studies have shown that dialysis and organ transplant patients, including renal transplantation patients, should follow photoprotective measures, as they are more prone to develop skin cancers. Use of sunscreening agents have prevented the development of premalignant skin changes in these patients. 53 , 54 Hence, physicians should educate these patients regarding the regular use of preventive measures against sun damage, including the regular use of appropriate sunscreens.

Formulations

Generally, sunscreens are available in the form of creams, lotion, gels, ointments, pastes, oils, butters, sticks, and sprays, which are considered over-the-counter (OTC) products. Less frequently used products include wipes, towelettes, powders, body washes, and shampoos, which are considered non-OTC products by the FDA. Of late, these types of products have been marketed as multifunctional cosmetic formulations incorporated into other cosmetics, such as moisturizers, facial foundations, and foam foundations (mousse). Spray or gel-based sunscreens are preferred in oily skin and acne. New sunscreens with microfine particles are found to be safe and effective in patients with acne and rosacea. Sunscreen filters are also added to hair care products, such as shampoo, to minimize sun damage to hair.

Sunscreen-containing moisturizers usually have SPFs between 15 and 30. Coverage foundations are transparent formulations containing titanium dioxide with an SPF of 2 while moderate coverage foundations are usually translucent with an SPF of 4 to 5.

Gogna et al 55 observed that the use of polymethyl-methacrylate (PMMA) microspheres of ethylhexyl methoxycinnamate (EHM) increases the efficacy of the latter by four times and also improves photostability of the preparation. Sprays containing sunscreening agents with high concentrations have been found to retain the medicaments on the top layers of skin, minimizing deeper penetration. 56

Studies have shown that microspheres increase the efficacy of sunscreening agents. 55 Incorporation of nanoparticles has shown to increase the efficacy of sunscreen agents in terms of superior UV protection and reduced whitening on the skin in comparison with the older generations of sunscreens. 57 Currently, formulations containing nanoparticles of TiO 2 and ZnO are available. However, studies have shown that nanoparticles of these two compounds cause cytotoxicity, genotoxicity, 58 , 59 and potential photocarcinogenecity. 60 In addition, nanoparticles of ZnO, even at a much lower concentration, may induce inflammation by releasing inflammatory mediators, such as cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α. 61 Sunspheres and microencapsulations are newer technologies in the preparation of sunscreen formulation. 12

Health Hazards of Sunscreening Agents

Although considered safe, sunscreening agents are not free from adverse effects. Sensitivity, though rare, can occur in the form of photoallergic reactions, including contact dermatitis. Photopatch testing helps to identify sensitivities. 62

There have been reports of increased incidence of melanoma as a result of sunscreen use. Gorham et al 63 reviewed the risk of developing melanoma as a result of sunscreen use and opined that those who live in latitudes greater than 40 degress may have an increased risk of melanoma. The reason for this may be because sunscreens absorb UVB almost completely, but transmit large quantities of UVA. 63 Sunscreen use may prolong the duration of intentional exposure giving people a false sense of security, especially when using products that have high SPF ratings, thereby increasing the risk of skin cancer. 64 A similar trend was observed in European countries as well. 65

A product assessment in the United States in January 2011 revealed that retinyl palmitate, a form of vitamin A, which is a widely used compound in cosmetics and sunscreens (as an antioxidant against the aging effects of UV radiation), is thought to increase the rate of the development of skin tumors and lesions. However, Wang et al 66 opined that its role in human carcinogenesis is doubtful as there is a lack of evidence. Fourschou et al 67 noted an exponential increase in vitamin D levels with the application of thinner layers of sunscreen after UVB exposure, indicating that application of thicker layers can cause a decrease in vitamin D levels resulting in its deficiency.

It is postulated that BZ-3 can disrupt the hormones in the body. The Centers for Disease Control and Prevention has detected BZ-3 in the 97 percent of Americans tested during biomonitoring surveys. Although there have been reports of adverse events with this agent, studies have shown that products formulated with 1 to 6% of BZ-3 do not possess a significant sensitization or irritation potential for the general public. 68

Exacerbation of acne and rosacea can also occur with the use of sunscreen agents that contain physical blockers, such as ZnO and TiO 2 , that are greasy and have large particle sizes, thereby blocking skin pores.

Effective Practice

According to the Environmental Working Group's 2010 Annual Sunscreen Guide, zinc and titanium-based sunscreens are considered more safe and effective than other products available in the United States. 69 Powder and spray sunscreens should be avoided, as they may lead to inhalation of particles, which is hazardous. The FDA recommends applying 2mg/cm 2 of sunscreen to achieve maximum benefits. Sunscreen should be reapplied every two hours as well as after sweating, toweling off, bathing, and swimming. It is recommended that sunscreen labels highlight the importance of reapplication. 70

Avoiding exposure to sunlight during the time of day when UV radiation is at its highest—between 10 am and 3 pm—is recommended. When sun exposure during this time is unavoidable, it is advisable to use sun protection (i.e., umbrella and sun protection clothing).

Causes of Sunscreen Failure

Underapplication and failure to reapply sunscreen every two hours are the main reasons sunscreens fail. Additionally, these agents are unaffordable by many in developing and underdeveloped countries. Sunscreen use year round is expensive, 71 which is why some people do not use sunscreen regularly. Another contributing factor to sunscreen failure is the mismatch between the labeled SPF and that delivered on application to skin and exposure to sunlight.

Promoting the Use of Sunscreen Agents

As the rate of sunscreen use is low, education and awareness about the hazards of sun exposure and the benefits of regularly applying sunscreening agents to reduce these effects must be spread. 23 , 72 , 73 Outdoor activities should be performed before 10 am or after 3 pm. 74 Education should target preadolescents so they develop the habit of using sunscreening agents at a young age, particularly as adolescents are more prone to seek sun exposure for intentional tanning purposes. 75 Organ transplant patients need to be educated regarding the regular use of sunscreening agents as well.

Lack of awareness among the public regarding the use of sunscreening agents is more evident in the United States, where only about 3 in 10 adults routinely practice sun-protection behaviors. Women and older adults have been found to practice sun protection more than others. 8

Role of Physician/Dermatologist

Physicians should be aware of the composition of sunscreen agents and the UVA protection factors of formulations. They should also instruct their patients about the proper application technique and insist on reapplication. Additionally, they should counsel preteens and adolescents regarding the regular and proper use of broad-spectrum sunscreens.

Recent Developments

Newer broad-spectrum chemical agents, such as bis-ethylhexyloxyphenol methoxyphenyl triazine (BEMT), methylene bis-benzotriazolyl tetramethylbutylphenol (MBBT), and butyl methoxy-dibenzoyl methane (BMDBM), have been found to be effective against UVA and UVB rays ranging from 280 to 400nm. These new agents have been formulated to be more fat soluble (oil soluble in cosmetic oils) to aid in efficacy and broad-spectrum activity. They are known to prevent the formation of free radicals induced by UV radiation to a significant level. These agents claim to be photostable, minimize erythema, and provide excellent anti-aging effects as well as protect the skin's antioxidant defense system. In studies, these new agents have shown to provide protection against intentional self tanning. Further, they also claim that there is no bioaccumulation, thereby exhibiting a good safety profile. Figure 6 shows the comparison of photoprotection by these newer compounds. 76

These new broad-spectrum sunscreen agents have been found to be compliant with regulatory guidelines in terms of PPD, SPF, COLIPA, and Boots star rating. They also claim to have the following advantages: instant action, longer duration of protection, improved cosmetic appearance of the skin in the form of less wrinkles, suitability for sensitive skin, and suitability for chikdren.

Future Developments/Scope

Bacterial-derived melanin has been shown to provide significant protection to fibroblast cells against UVA radiation. It is a promising product that helps to keep UVA-irradiated skin from pigment darkening, especially in those with photosensitivity. 77

The use of antioxidants has shown to minimize the release of oxidants after excessive sun exposure on unprotected skin. 15 A compound that is effective in protecting against complete UV spectrum and infrared radiation is welcome.

Despite the efforts of physicians and regulatory authorities to spread awareness regarding sunburn, skin cancer, and the benefits of regularly using sunscreening agents, treatment adherence is low. 78 Providing cosmetically acceptable preparations and educating people about following the application instructions, is a challenge often faced by treating physicians. Pricing sunscreens reasonably and making them water resistant and non-sticky are a few of the challenges faced by manufacturers. Manufacturers must also consider sensitization reactions, especially in those having eczema or photodermatoses. 79 Narrow-spectrum sunscreening agents, especially those that absorb only UVB rays, may contribute to the development of melanoma at latitudes over 40 degrees due to transmission of UVA rays in large amounts. 63

Use of sunscreening agents is beneficial in minimizing the occurrence of skin cancers in people with fair skin. However, the same effect on Asian skin is debatable, as this skin type is considered to be resistant to skin cancers. Sunscreen use is advisable in young adults to prevent and minimize other photodamaging effects. Affordability and proper application techniques are the challenges that must be addressed in order to achieve regular sunscreen usage. The authors recommend further comparative studies on sunscreens as well as studies on the Indian population, as there is insufficient data in this population.

DISCLOSURE: Dr. Latha, Ms. Sham Shinde, Dr. Bellary, and Mr. Rao are employed by Dr. Reddy's Laboratories Ltd. and are stakeholders in Dr. Reddy's Laboratories Ltd. Dr. Krishnankutty, Dr. Kumar, and Mr. Varughese were former employees of Dr. Reddy's Laboratories Ltd. and are presently not stakeholders in Dr. Reddy's Laboratories Ltd. Dr. Martis, Dr. Bangera, and Dr. Shobha report no relevant conflicts of interest.

The 11 best sunscreens for healthy skin 2024

A s a beauty expert, there are two cardinal rules to live by. One, drink more water; two, wear SPF daily. It is basic beauty lore. Even so, during my almost decade-long tenure as beauty director of Elle magazine, I did not always practise what I preached, and I have the freckle-shaped skin damage to show for it. The benefits are obvious: research has proved that daily application of sun-protection factor 15 or above lowers your chance of developing certain skin cancers by 50 per cent , plus, of course, it discourages premature skin ageing. 

My issue with SPF was the reaction and tolerance of my sensitive skin, which, if I’m honest, felt more of an immediate priority on a day-to-day basis than protecting the future of my face. And I’m not alone in this. A YouGov survey conducted by skincare company Face The Future showed that only 22 per cent of the UK apply SPF daily, and just 53 per cent of British women are worried about ageing from sun damage. 

In my case, I hadn’t found the right product for my skin, but they’ve come on light years since the white-cast, comedogenic formulas that gave SPF a bad name . The sun protection market has shown consistent and significant growth and, in turn, beauty brands have expanded their ranges to tackle specific skin concerns, launching suncare products to solve many problems. But with greater choice comes greater confusion.

The facts are clear, though: SPF is vital. It is important for protecting your skin from both burning and ageing ultra-violet radiation, essential for your health, and, as I have come to experience with the right products, can deliver a skin-beautifying boost, with benefits.

What to look for in a sunscreen

Your key non-negotiables are broad spectrum (protection against both UVA & UVB rays), and a minimum SPF of 30 (but ideally 50). To protect against all harmful rays – such as blue light, visible light and infra-red too – a full-spectrum SPF is even better.

Dr David Jack is an aesthetic doctor and skincare expert with a skin clinic on Harley Street. He tells me: “It is paramount to not only consider SPF as a way of preventing sunburn, but as the critical element in a comprehensive, anti-ageing skincare strategy .” But not all SPFs are created equal. “A minimum of SPF 30 will block approximately 97 per cent of UVB rays, with higher SPFs offering greater protection. The level of UVA [the deeper-penetrating UV rays] protection is less than this.”

Mineral versus chemical sunscreen

If, like me, you have skincare concerns and might be SPF-avoidant, it is best to opt for a non-comedogenic sunscreen. This simply means non pore-blocking and therefore the difference between a good and a bad skin day. Most mineral sunscreens are non-comedogenic, but lots of modern chemical formulas have been adapted to make sure they aren’t causing skin irritation. Mineral sunscreens include natural ingredients, such as zinc oxide and titanium dioxide, that sit on the skin to physically block the sun’s rays; chemical formulas use effective ingredients such as oxybenzone that are absorbed into the skin to convert UV rays into heat, which is then released from the body. 

Dr Jack believes the distinction between the two is largely irrelevant when it comes to efficacy. “It is the level of protection that matters. The use of daily SPF is important year round (not just in the summer) as UVA levels tend to be at similar levels throughout the year and can even penetrate through glass.”

Apply it correctly

Many studies have shown that we don’t use sunscreens properly. With that in mind, it is up to you to get the most protection from your SPF. The number of times sunscreen should be reapplied over the course of the day is dependent on your level of activity, the amount of sun exposure and the type of product. Dr Hiva Fassihi is a consultant dermatologist for skincare company La Roche-Posay and recommends applying your SPF 20-30 minutes before going outside, with reapplication of sunscreen every two-three hours.

She shares some useful tips: “The amount of UVA and UVB protection a sunscreen provides is related to how thickly it is applied on to the skin, so be generous with your sunscreen application.”

For the average adult, use 30-50ml of SPF – about the size of a shot glass – to cover the whole body. For the face, remember the two-finger rule; dispense two strips of sunscreen along your index and middle finger and apply for full facial coverage. 

And keep topping it up. Dr Fassihi warns us to “ignore ‘once daily’ or ‘water resistant’ branding and always reapply your sunscreen every two to three hours, and straight after swimming or towelling, in order to maintain protection”.

Best sunscreen for oily skin

Ultra Violette Lean Screen Mineral Mattifying SPF 50+, £34

A mineral-only sunscreen that has a subtly matte finish to take and keep the sheen off. Ultra Violette is something of a covetable cult makeup-like brand of the SPF world.

Additional skincare benefits:

• With vitamin C for antioxidant protection as well as extra, non-comedogenic moisturising ingredients
• Pump application

Best sunscreen for dry skin

CeraVe Facial Moisturising Lotion SPF 50, £16.50

An easily absorbed daily moisturiser with SPF included so it is a multi-tasker that delivers a full 24 hours of hydration. It’s like a drink or water for thirsty skin.

• Ceramides and hyaluronic acid provide skin-barrier strengthening benefits.

Best sunscreen for acne-prone skin

Dr Sam’s Flawless Daily Sunscreen SPF 50, £31

Dr Sam Bunting from Harley Street Clinic explains: “SPF is super-important for blemish prone skin as it protects against post-inflammatory hyperpigmentation, those pesky dark marks that spots leave behind.” This actively calms reactive skin with a soft focus finish so it works as an excellent base for concealer.

• It contains 5 per cent niacinamide which helps to brighten and boost skin whilst helping keep pores clear and skin calm

Best sunscreen for sensitive skin

La Roche Posay Anthelios UV MUNE 400 Invisible Fluid, £20

Brilliant for all skin types, but specifically formulated for sensitive and reactive skin, it is ultra water, sand and sweat resistant, lightweight and totally invisible.

• Gives unique extra protection against the deeper penetrating UVA rays responsible for premature ageing.
• Fluid application

Best anti-aging sunscreen

Institut Esthederm Into Repair SPF 50+, £66

With full spectrum protection, this is designed for Hypersensitive, intolerant skin, with loss of firmness. Also brilliant for very fair, post- treatment, or sensitised skin. A brilliant high-value option.

• Regenerative active ingredients to help firm the skin, smooth fine lines, and stimulate collagen and elastin production
• Tube application

Best sunscreen with tinted formula

Obagi Tint Sun Shield in Cool or Warm, £64.09  

The option to choose a warm or cool toned tint is brilliant for the most complimentary and complexion enhancing finish. It gives a beautiful natural glow and skin feels enriched and protected. A personal favourite.

• Non-comedogenic, hypoallergenic, and dermatologist-tested

Best sunscreen for outdoor activities

Lancaster Sun Sport Cooling Invisible Mist, £25.60

This super-fine mist can even go onto wet skin and is resistant to both water and sweat. It’s a great, skin-cooling and comforting  all-rounder with serious staying power and true ease of use. One for the gym bag.

• A significant cooling effect to refresh the skin with brilliant broad spectrum protection
• Mist application

Best budget-friendly sunscreen option

Garnier Ambre Solaire Super UV with Vitamin C, £9.50

Ultra lightweight and serious value for money, it has a light invisible, non greasy finish and the perfect addition to your facial skincare routine.

• With vitamin C, glycerin and vitamin E, it is anti-dark spots, glow-boosting and helps to even out skin tone

Best sunscreen for water activities 

UltraSun Very High SPF 50 Sports Spray Formula, £28

A transparent and fast absorbing non-greasy formula with the most serious staying power. Marketed as ‘one application’ which is tempting, but always top up after the water to be safe.

• Hypoallergenic and non-comedogenic with antioxidant Vitamin E

Best sunscreen for lips

Sun Bum Moisturising SPF 30 Lip Balm, £3.83

While many SPF lip balms can feel quite drying or non-absorbent, this has a  lovely creamy formula that effectively protects and nourishes your thinner-skin, and therefore extra prone to sun damage, lips.

• Aloe and vitamin E for superior and hydration
• Bullet balm application

Best sunscreen for families

Altruist Family Sunspray, 12.50

Created by a dermatologist and skin cancer surgeon, the SPF 50 spray is suitable for the whole family, including babies from six months old, so you only need one bottle for the beach.

• Paraben free, gentle for the most sensitive skin and dermatologist specification broad spectrum
• Trigger spray  application

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