WASHINGTON — As summer heat hits its peaks, more people are headed out to the beach or the pool to bask in the sun. And while everyone should be using sunscreen to protect from the sun's potentially harmful rays, sometimes there's a dispute over whether going above an SPF 50 is really that much more beneficial; So we're verifying.
THE QUESTION:
Do sunscreens with SPF over 50 do a better job?
OUR SOURCES:
- Dr. Adam Friedman- professor & chair of dermatology, The George Washington University
- Dr. Stephen Wang- director of Dermatologic Surgery and Dermatology, at Memorial Sloan Kettering Cancer Center
- American Cancer Society
THE ANSWER:
SPFs over 50 do a better job, particularly because people don't wear enough of it.
WHAT WE FOUND:
According to the American Cancer Society, SPF (sun protection factor) correlates to how much protection a sunscreen offers against UVB rays. They say that SPF 15 filters 93% of UVB rays, SPF 30 filters 97%, SPF 50 filters 98% and SPF 100 filters about 99%.
But here’s the twist: that’s only true if you use the right amount of sunscreen, an entire shot glass-full, reapplied every two hours.
“This is based on the assumption that people apply a very large amount of sunscreen which they absolutely do not," Dr. Friedman, chair of the dermatology department at GWU, said. "So technically above an SPF 50 you're not going to get that much more protection from UVB; however, because people don't apply enough, there is a dilutional effect. So for example, 100 ends up being like a 50, 50 ends up more being like a 25."
He added: "So that's where the higher SPF might be helpful, because we don't do it correctly."
Dr. Wang says most people use less than a third of what they should, but says that all things being equal, yes, you should opt for that a higher SPF because more coverage is more coverage.
Now whether the difference between SPF 50 and SPF 100 is marginal or meaningful depends on how you look at it. If you’re comparing 98% of protection to 99%, it may seem insignificant.
But if you think about how many harmful UVB rays are seeping in, you may feel differently. Then, you're comparing 2% of radiation vs. 1%, meaning you're cutting your skin damage in half.
Either way, both our experts agree that yes, a higher SPF is useful, especially since very few people actually use the amount they’re supposed to.
The CDC recommends using a broad spectrum sunscreen with at least an SPF 15.