When it comes to preventing skin cancer, sunscreen is essential. There are two main types of sunscreen — chemical and physical (or mineral). Both are effective, says Tahl Humes, DO, medical director of VITAHL Medical Aesthetics in Chicago. But what’s the difference between the two?
“Chemical sunscreens contain active ingredients that absorb the UV rays as they enter the skin, while physical sunscreens sit on the surface of the skin and deflect UV rays away from the skin,” she says.
However, some chemical sunscreens contain ingredients that may have adverse side effects. The Environmental Working Group says ingredients including oxybenzone, octinoxate, and avobenzone may disrupt hormones when absorbed through skin, though the Food and Drug Administration is still evaluating these concerns.
Reapplying sunscreen is key. Even with the strongest sunscreens, protection wears off over time. Humes recommends applying sunscreen before makeup. Even if makeup contains SPF, it’s not enough sun protection, so use a mineral sunscreen powder on top of makeup, she says.
Apply sunscreen 20 minutes before sun exposure and reapply every two hours, more often
if swimming or sweating. If that’s difficult, invest in sun-protective clothing that can protect your skin all day.