Skin cancer is the most common cancer in the United States, and data shows that one in five Americans will develop skin cancer by age 70. For healthy skin, experts advise that protection is important not only for preventing cancer, but for anti-aging benefits as well.
But there are thousands of products on the market, and many social media accounts, blogs and forums dolling out advice and sharing skincare routines, which means there is a lot to parse when it comes to skin health, particularly on the topic of sunscreen.
There are many misconceptions, and just as many questions like “who needs sunscreen?”, “do I really need to reapply sunscreen throughout the day? When? How often?” and “do I have to use sunscreen even in winter?”
CNBC Make It spoke to Dr. Adam Friedman, professor and chair of dermatology at GW School of Medicine and Health Sciences, and he shared some facts about sunscreen that may surprise you.
1. Applying sunscreen is just as important as brushing your teeth
Many Americans don’t think applying sunscreen is super important. Only 17% of U.S. adults reported using sunscreen daily, according to a 2024 survey of 2,200 Americans.
Friedman wants to shift the narrative: “I want people to think about sunscreen use like they would brushing their teeth.”
If you wouldn’t leave your house without brushing your teeth, he wants you to view sunscreen in the same way. “Just like we’re protecting our teeth, we need to protect our skin, which is our largest organ,” Friedman says.
2. Most people forget to apply sunscreen to their eyelids, ears and lips
Before heading out for the day, you probably apply sunscreen to your face, but there are common areas that get overlooked.
“I think a lot of people avoid the lips, which are actually more susceptible to harm from UV radiation, because it’s missing certain things that our skin has,” Friedman says. If you’re worried about accidentally getting sunscreen in your mouth, there are lip balms with SPF in it, he adds.
He also finds that people forget to apply sunscreen around their eyes and on their eyelids, and research confirms it’s pretty common. Because the skin of your eyelids is so thin, it is even more susceptible to injury from UV radiation, Friedman notes.
Other areas that people miss are their ears. “I see a lot of skin cancer on what’s called the helical rim. It’s the very top of the ear, and that’s not an easy area to treat for skin cancer,” Friedman says.
“I tell my patients, ‘I’m glad you’re getting the face. Just do an extra squirt for the ears, the neck and the back of the hands.’ That’s probably an everyday exposure.”
3. There’s no difference in feel or cost, but higher SPFs are more efficient
“You can’t say a sunscreen protects against skin cancer or accelerated skin aging, unless you’re SPF 15 or higher,” Friedman says.
The American Academy of Dermatology’s recommendation for sunscreen is:
- SPF 30 or higher
- Water resistant
- Broad-spectrum protection (which protects against UVA and UVB rays)
SPF 30 blocks about 97% of UVB rays, and SPF 50 can protect against about 98%, Friedman explains. Most people aren’t able to get 100% protection, unless they “apply two milligrams per centimeter squared of sunscreen. That’s a lot of sunscreen,” he says.
“That’s why I do push for higher SPFs. There’s really no difference in the feel and the texture or cost. It’s more that I know you’re not going to put the right amount on, so at least it keeps you in a range that is still going to be effective.”
4. Aim to reapply every 2 hours on days when you’re outside for a while
Dermatologists suggest reapplying sunscreen every two hours, but Friedman is realistic about how difficult that can be.
“I apply in the morning, but I don’t go outside at all, and I’m not really near windows,” he says. Often, he applies only once a day.
On days where he plans to be outside more than usual, he suggests being more intentional about applying every two hours. If you’re sweating a lot or just got out of a pool, you’re likely losing your layer of sunscreen, and should also reapply.
“Technically you should be reapplying every two hours. I say technically, because I’m a realist and who’s going to actually do that,” Friedman says. “Do the best you can.”
5. You need to wear sunscreen in every season, even winter
“Sun protection is a year round thing,” Friedman says. “Depending on the time of year, depending where you are in the world, there are various factors that will affect the UV index. So I think that it’s not a one-size-fits-all.”
Even if the UV index is relatively low, Friedman notices that people are a lot more likely to remember to use sunscreen in general when they stick to a daily habit of applying it.
There’s a common skin condition called dermatoporosis that typically affects people when they’re older. The condition describes the way skin can get fragile and bruise easily, and it “most commonly occurs on the forearms, because that’s where we forget to protect,” Friedman says.
“These big purple splotches on their arms, or these white, little star shaped scars, it’s this chronic injury that we accumulate over time. I can guarantee you a lot of accumulations are not from the summer, but probably during the winter when we’re not protecting ourselves appropriately.”
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