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Think you're wearing enough sunscreen? You're probably not

A dermatologist shares exactly how much sunscreen you need to wear each day.

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- 03:55
mother applying sunscreen to toddler

Most people apply less than half of the recommended amount of sunscreen.

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Skin cancer, sun damage, dark spots and wrinkles -- those are just a few of the risks of not wearing enough sun protection on your skin. Whether you care more about your health risk or your future skin appearance, listen up: you're probably not wearing enough sunscreen

Everyone should wear sunscreen with at least SPF 15, since anyone is at risk for getting skin cancer. Of course, you may need more than SPF 15 if you're spending time in the sun. SPF 30 or higher is your safest best for stronger protection. Sunscreen application isn't a "one-and-done" scenario, either. You should reapply sunscreen regularly, at least every two hours and more frequently if you're sweating a lot or swimming. 

But is it enough to apply a small dab of sunscreen, or should you lather a handful on? And what should you do if you use products like makeup or moisturizers that already have SPF in them? Keep reading for more guidance from dermatologist Dr. Caren Campbell.

Read more: Best sunscreens for dark skin in 2021

How to apply an adequate amount of sunscreen

For starters, Campbell says that most people aren't applying nearly enough sunscreen. "Studies show that most people only apply 25-50% of [the] recommended amount of sunscreen," says Campbell. And if you don't apply enough, you may not be getting the amount of protection that's listed on the label.

The amount that Campbell recommends for the average adult is "1 ounce of sunscreen, which is the size of a shot glass," she says. She prefers a liquid sunscreen over a spray, even though they can be convenient. "Spray sunscreens are always going to fall at the bottom of our list as they're difficult to ensure good coverage on the exposed areas of the body," says Campbell. 

If you have a hard time envisioning what 1 ounce looks like, esthetician and influencer Tiara Willis popularized the "two-finger rule," which says that you should apply two fingers' worth of sunscreen.

When you apply your sunscreen, don't forget to apply to those often forgotten areas, like your ears, the tops of your feet, head (including the scalp) and neck. "Some of the most aggressive skin cancers occur on your temples, ears and lips oftentimes because there are areas of the body that stick out and get more sun, but also because we forget to lather them in sunscreen," Campbell says. 

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Some skincare and makeup products contain SPF, but Campbell says you should still wear sunscreen.

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If there's SPF in my makeup/moisturizer/serum, do I still need to wear sunscreen? 

Campbell says this is one of the most common mistakes she sees patients make with their sun protection: You can't assume that the (typically small) amount of SPF that's in your makeup or skincare is enough protection. "Most of my new patients come in using moisturizers with sunscreen or makeup that contains sunscreen and for them, they think this is sufficient and it's not," says Campbell. You'll still need to apply a good facial sunscreen in addition to whatever is in your makeup or other products for best results, since many of these products are not SPF 30 or higher or they don't provide broad spectrum protection, according to Campbell.

"Most sunscreen in makeup and moisturizer is chemical sunscreen which doesn't work as well or have as complete protection from harmful UV rays as mineral sunscreens, which are physical blocking sunscreens," says Campbell. Mineral sunscreens work by reflecting the sun off of the skin, rather than absorbing UV rays, which chemical sunscreens do. Campbell recommends mineral sunscreens over chemical because she says they are more effective: "You can also reapply dry sunscreen or powder sunscreen over makeup as you need to reapply every two hours or if you sweat."

When to apply sunscreen

You have to apply sunscreen at least 15 minutes before you head out into the sun. "Especially with chemical sunscreens, these need to be applied 15 minutes prior to going outside as they need time to start working," Campbell says. "You need to reapply every 2 hours or if you sweat or swim."

Keep in mind that even if you use "waterproof" or "water resistant" sunscreen, you still need to reapply after you are in water. "Waterproof is no longer a thing -- it's water resistant, so when you get out of the pool, reapply," says Campbell.

It never hurts to layer your sunscreen -- even if that means adding extra pieces like hats, clothing, or anything else that shields you from the sun's rays. "SPF clothing, hats, sunglasses, beach umbrellas - all these things help especially when we are sweating and swimming," Campbell says. 

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The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.