For Men’s Health, Brian Underwood investigates the flood of sunscreen misinformation on Instagram and TikTok, where influencers push inaccurate data about chemical UV filters, play chemist and promote their own DIY formulas, or even encourage no sun protection at all. Underwood sorts fact from fear, talking with dermatologists, chemists, and professionals who are working to reshape the messaging around sun exposure and sunscreen.

Environmental concerns may have also shown up in your feed, with suggestions that these same filters are poisoning our oceans, giving rise to a whole category of sunscreens labeled “reef safe”—a meaningless marketing term that’s not regulated by the FDA (the same goes for products labeled “natural” or “organic”). Dr. Nelson’s point about “low-relevance models” is something to consider here too: The research demonstrating that oxybenzone, octinoxate, and other active ingredients may lead to reef bleaching was done in a lab setting where coral was exposed to levels of these chemicals significantly higher than has been found in the natural environment. It conveniently left out the fact that inorganic filters like zinc oxide (the one typically used in “reef safe” formulas) would have the same effect in similar doses.