I used to think I was pretty good with sunscreen. I followed all the rules: I applied it every morning, no matter the forecast. I kept powder sunscreen in my bag for midday reapplication. I splurged on the luxury SPFs that promised the hydrating, silky-smooth texture of my favorite moisturizers. But once I became a beauty editor, I learned that even the most diligent sunscreen wearers—myself included—likely make sunscreen application mistakes that leave skin vulnerable to sun damage.
“Think of SPF like a clingy friend: it needs attention every two hours or it stops doing its job,” says Mona Gohara, MD, a board-certified dermatologist at Dermatology Physicians of Connecticut. In other words, sunscreen isn’t a one-and-done situation. It’s one of the most effective ways to lower your risk of skin cancer, but only if used correctly, says Brian Hibler, MD, a board-certified dermatologist at Schweiger Dermatology. That means applying the right amount, covering every exposed area (even the ones you don’t think about, like the armpits!), and reapplying often. And no, the SPF in your tinted moisturizer—or a quick mist of spray sunscreen—won’t cut it.
