A new study finds that only 40 percent of the most popular, well-regarded sunscreens meet American Academy of Dermatology criteria.

By Liz Steelman
Updated July 07, 2016
Sunscreen should be part of your regular routine, but when you’ll be outside for an extended time, you need to be sure you’re applying one that’s broad-spectrum. Look for a sunscreen with stable UVA shields, like Mexoryl and Helioplex, which can be used on the body, too. Be careful where you stash it, though—as in, never in a glove compartment, especially during the summer (ditto for lip balm with SPF). Once the car heats up in the sun, the high temperatures can cause the sunscreen’s active ingredients to degrade, which means you won’t be getting the SPF that’s indicated on the bottle. In fact, you might be applying nothing more than a thick moisturizer. (And the lip balm can melt, to boot.)
Plamen Petkov

How do you pick a sunscreen? You might look for one that doesn't leave white residue, smells good, and isn’t greasy. But according to a new Northwestern University study, consumers often end up choosing less effective products—all because of how they feel. In fact, only 40 percent of the most popular, well-regarded sunscreens in the study met the American Academy of Dermatology's (AAD) recommended criteria for adequate sun protection. What's more? Your preferences might have you paying up to 3,000 percent more for the same protection.

For the study, which was published in JAMA Dermatology, researchers looked at Amazon's top 65 sunscreens, based on the greatest number of reviews that were four stars or more. Researchers analyzed the product description, as well as descriptive information from the top five “most helpful reviews.” Sunscreens were evaluated on affordability, cosmetic elegance, separate ratings, product ingredients, performance, and skin compatibility. They were also measured against the AAD guidelines, which require a product to be broad spectrum (blocking both UVA rays, which can cause aging, and UVB rays, which can cause skin cancer), have an SPF of 30 or higher, and be moisture resistant.

“We are often asked to recommend sunscreens, and we wanted to know what consumers prefer,” Steve Xu, lead study author, said in a statement. “This way we are suggesting popular products they will actually use that will protect them.”

Researchers found that consumers were more likely to like and buy a product for cosmetic elegance (how it felt on the skin at application, the color, or the scent) over perceived performance (whether or not it was effective at preventing sunburn). Out of the top 10 most reviewed, highly rated sunscreens, only five met AAD criteria. The most common pitfall? That a sunscreen was not water or sweat resistant. The following did meet the criteria:

Surprisingly, 9 out of 10 of the lowest cost (according to price per ounce), highest rated sunscreens adhered to AAD criteria. The only one that didn’t was zinc oxide powder, which is often used for homemade sunscreens. Here are the low-cost sunscreens that met the AAD critera:

Need to brush up on your sunscreen basics? Here, sunscreen mistakes even smart people make. And watch out: your sunscreen might not have the SPF you think it does.