7 burning questions about sunscreen, answered

Anyone who’s suffered the torment of a sunburn can tell you how they wished they’d done a better job protecting their skin. Sunscreen, one of the tools in the sun-protective tool belt, is non-negotiable, regardless of the weather or your skin type. Any dermatologist will say so; they’re likely to recommend everyone include it in their daily skin-care regimen. Even so, many American adults aren’t great about wearing sunscreen: Only 12 percent of men and 29 percent of women reported always using sunscreen when outside on a sunny day for an hour or more, according to a 2020 National Health Interview Survey.

Sunscreen — which works by blocking ultraviolet radiation from the sun — has been shown to prevent skin cancer, wrinkles, pigmentation, and sunburn. Taken together with other smart sun practices, like wearing sunglasses and a hat that covers the face and ears and seeking shade, regular sunscreen use can lower your risk of skin cancers, both among lighter-skinned people (who are more susceptible to skin cancer) and people of color, who are more likely to die from skin cancer due to a delay in detection.

Not all sunscreens available in the US (and elsewhere) are built alike. In the European Union, for instance, sunscreen is regulated as a cosmetic product so new ingredients have been introduced into their formulas, compared to the US where new ingredients haven’t been approved in over two decades. Some sunscreens leave a ghostly cast; others can exceed $50 for just a few ounces of product. To help guide you toward the sunscreen of your dreams, experts provide clarity on common questions about the product.

The sun emits ultraviolet — or UV — rays that can damage the skin. Two types of UV rays cause sunburns: UVA and UVB. UVA rays penetrate the skin more deeply and are a greater contributor to skin cancer, says Kelly Dobos, a cosmetic chemist and professor of cosmetic science at the University of Cincinnati and the University of Toledo. When sunscreen was first regulated by the Food and Drug Administration in the 1970s, “our understanding of damage from the sun was really limited to UVB,” Dobos says. “As our knowledge about the damage from the sun grew to incorporate deeper penetrating UVA rays, we now have broad-spectrum sunscreens that cover UVB and UVA.”

UVA rays are what Hope Mitchell, a dermatologist and founder of Mitchell Dermatology, calls “aging rays.” They can pass through windows and glass and prematurely age your skin, causing wrinkles and age spots, Mitchell says.

You’ll want a sunscreen that protects against both UVA and UVB rays, referred to as broad spectrum, so make sure “broad spectrum” or other verbiage that mentions protection against both UVA and UVB rays is referenced on the label.

Sunscreens fall under one of two consumer categories: chemical and mineral sunscreens. However, from a chemistry perspective, both types of sunscreens are made of chemicals, Dobos says. Don’t be fooled: She often encounters people who believe mineral sunscreens are “natural.” They’re not — the ingredients used in those sunscreens aren’t extracted from the ground and ready for use in a cosmetic product.

Mineral sunscreens work by creating a barrier on the skin that reflects UV rays. The main ingredients in these sunscreens are titanium dioxide and zinc oxide, which can leave a white or ashy cast on the skin. Chemical sunscreens get absorbed into the skin and “help create chemical reactions that lead to repelling the UV rays,” says Rachel Reynolds, interim chair of dermatology at Beth Israel Deaconess Medical Center and assistant professor of dermatology at Harvard Medical School. Ingredients in chemical sunscreens include avobenzone, homosalate, octocrylene, octinoxate, octisalate, and oxybenzone. These sunscreens can feel greasy.

“There’s pros and cons to each type,” Dobos says. (More on this shortly.)

In 2019, the FDA announced two ingredients — PABA and trolamine salicylate — were not safe and effective and are no longer permitted in sunscreens, says dermatologist Mary Hall, a spokesperson for The Skin Cancer Foundation.

Regardless of what type of sunscreen you prefer, make sure it’s water and sweat resistant, Hall says.

One of the biggest obstacles to regular sunscreen use is finding one you’ll actually want to apply every day. The chalky residue from mineral sunscreens isn’t an ideal look for most people, especially those with darker skin types. Oily chemical sunscreens or sunblocks with irritating fragrances can also be annoying for those with sensitive skin or allergies.

Each brand of sunscreen has a different formula — and many of these have improved recently to address consumer pain points. Dobos is a fan of Supergoop sunscreens; these are primarily chemical sunscreen products, but without the oily feel typical of these sunscreens. “They have great formulas that work with makeup when you apply it,” Dobos says. She’s also a fan of Neutrogena sunscreens — the brand offers both chemical and mineral formulas — which come in lotions, sprays, and sticks. The Skin Cancer Foundation has a database of sunscreens the organization recommends, including CeraVe Hydrating Sunscreen Face Sheer Tint and La Roche-Posay Anthelios Face Mineral Sunscreen.

To address the white residue left by mineral sunscreens, some manufacturers have begun offering tinted sunscreen. “They typically contain iron oxide,” says Ronda Farah, an associate professor of dermatology at the University of Minnesota. “That’s what I use because my skin tone is olive.” Other options for non-streaky screens include chemical-based gel sunscreens, which are clear when applied, or sunscreens with a yellow tone, Farah says.

For those with sensitive skin or allergies, Farah recommends mineral sunscreens — those with titanium dioxide and zinc oxide ingredients. One of the most common sources of allergy in cosmetic products is fragrance, Dobos says, so opt for a fragrance-free sunscreen. Mitchell recommends Neutrogena Sheer Zinc Face Mineral Sunscreen SPF 50 and Neostrata Sheer Physical Protection.

Reynolds recommends mineral sunscreens for children since they’re less irritating. The FDA does not recommend sunscreen for infants under 6 months since they may be susceptible to rashes; instead, keep them out of direct sunlight and keep them covered up with long sleeve shirts, pants, and hats.

Because there are so many sunscreen options, Farah says to buy three, and be prepared to only like one of them for everyday use on the face. “The other two,” she says, “demote to the body.” Don’t spend a ton of money here — you can get an effective sunscreen that feels great for a low cost.

Some manufacturers and beauty stores stock sunscreens that can run up to $60 for a wee bottle. “You don’t have to buy expensive fancy sunscreens,” Farah says. “You can buy stuff from Target or Walmart as long as it has that sun protective factor and it’s not irritating skin.”

While higher-end sunscreens can feel a little nicer or contain tints and makeup, it doesn’t materially change the efficacy of the sunscreen. If you prefer your sunscreen lightweight, matte, or want it to double as makeup, it may be worth it to spend a little more. “I typically say spend the money on the fancy one for your face and neck,” Farah says, “and the cheaper sunscreens on the body.”

Sun protection factor — also known as SPF — refers to the amount of time you could stay out in the sun without burning compared to if you weren’t wearing any sunscreen at all. “So an SPF of 30 would mean that you could stay out in the sun 30 times longer with this sunscreen on and not burn relative to having no sunscreen at all,” Reynolds says.

Experts recommend wearing sunscreen with SPF 30 or higher. Beyond SPF 50, any additional protection is negligible since the UV rays are already effectively blocked. “The difference between an SPF of 15 and 30 in terms of the overall efficacy is going to be greater than if you’re jumping from an SPF 30 to an SPF 50,” Reynolds says.

Pay attention to the expiration date on the bottle, too. Hall recommends people purchase a new bottle of sunscreen at least once a year.

There are a few rules of thumb regarding when and how much sunscreen you should use. Timing-wise, apply sunscreen 30 minutes before going outside, Hall says. As far as quantity, experts recommend a shot glass sized amount of sunscreen for the entire body and a nickel-sized amount for your face. “A thicker layer will protect better than a thin layer,” Reynolds says. Applying too thin a layer of sunscreen will result in less SPF protection than what’s labeled on the bottle.

The best way to ensure you’re applying enough sunscreen is to use a cream-based sunscreen, Reynolds says. Spray sunscreens provide a thinner coating, and are therefore offering less protection. However, spray sunscreens are convenient for use on the scalp, Reynolds says.

Keep in mind that the best sunscreen option is one that you’ll readily use. So if spray options are your preference, they’re better than nothing. Farah also uses stick-based sunscreens for her children since they’re easier to apply.

One application isn’t enough if you’re spending extended time outdoors. Reapply every two to four hours if you’re in the sun, experts say.

Regardless of whether you’re soaking up the sun, wear sunscreen on your face and neck every day, Farah says, as UV rays can penetrate windows in your home and car.

In the United States, sunscreens are considered an over-the-counter drug and are regulated by the FDA. Therefore, ingredients in sunscreen must be deemed safe and effective by the FDA. In places like the European Union, sunscreens are still regulated, but they’re considered cosmetics, “and it’s easier to get a new active ingredient approved,” Dobos says. No new sunscreen ingredients have been approved by the FDA since 2000. Elsewhere in the world, sunscreens contain newer ingredients, like bemotrizinol, which could potentially be approved by the FDA by 2025, Dobos says.

By skirting drugstores and ordering international sunscreens online, consumers can get their hands on newer formulations, but ones that are not approved in the US. While some experts find no reason to import sunscreen from beyond American shores, if you are looking to try something different, Dobos advises caution: Only purchase from a reputable company (manufacturers with global operations like L’Oreal, Unilever, Johnson and Johnson are best) and check to see if the FDA sent a warning letter to the company for not being safe or effective. “A few years ago, there were some Korean sunscreens that a company had tested by an independent laboratory and it did not perform up to the label claim of the SPF,” Dobos says.

Finding the perfect sunscreen may require some trial and error, but regular use is crucial, no matter your age or skin type. It’s never too late to start a healthy skin habit — and keep wrinkles, sun spots, and, most importantly, skin cancer, at bay.