Are You Undermining Your Sunscreen?

Effective as sunscreen is at shielding our skin from damaging and potentially cancerous UV rays, it only works when it’s used correctly. To make sure you’re fully protected this summer, avoid these common mistakes that could leave you more exposed than you realize.

You’re probably skimping.

Too many people are applying half the recommended amount of sunscreen (which is two milligrams per square centimeter of skin). As a result, they’re getting only about half of the SPF value on the label. In other words, if you’re using a broad-spectrum sunscreen with an SPF of 30 – as you should be – you’re really getting the efficacy of an SPF 10 or 15.

To help you allocate the right amount, try this: Envision a shot glass filled with sunscreen – or actually fill one, if it helps. That’s how much you should be using to cover your entire body. And then squirt out another nickel-size dollop specifically for your face.

You forget to reapply.

If you put on sunscreen before you head out the door in the morning, good for you. But don’t leave the bottle at home. Most sunscreens work for about two hours, which means, if you make a mid-morning coffee run, your skin’s going to be vulnerable. 

Studies have shown that just a few minutes outside without sunscreen can be damaging. One in particular, published in the peer-review journal Science, discovered the sun immediately triggers a reaction that damages the DNA in unprotected skin cells. The reaction will continue for a few hours. And the damaged DNA can ultimately lead to skin cancer, one of the study’s authors said.

So, try get into the habit of reapplying every couple of hours. Even on cloudy days. And when you do, be meticulous. Your dermatologist will tell you that skin cancer commonly crops up around the hairline and brows because they’re two spots that almost everyone misses.

You think that sunscreen only comes in a bottle.

With sun-protective clothing, you don’t have to worry about sweating it off or changing every couple of hours. I’m not saying opt for a wide-brimmed hat over sunscreen. Instead, supplement your facial sunscreen with one. Think of it as an extra layer of protection.

Certain sunglasses are also an effective broad-spectrum sunscreen. But recent research suggests that effectiveness wanes over time. To ensure yours are blocking UV rays, replace them every couple of years and keep them in a case when you’re not wearing them. Scratches on the lenses, even tiny ones, can let UVA rays through.