If you’ve perused the sunscreen aisle — and hopefully you have at this point in the summer! — you’ve seen the selection of SPFs available. There’s everything from SPF 15 to SPF 100 and beyond. It can be confusing to figure out which one is best for you, and to know if using a sunscreen with a super high SPF (like SPF 100) is truly better than the standard SPF 30. We turned to the experts to get the scoop.
What exactly is SPF?
“SPF is defined as ‘sun protection factor,’ and it means how well a sunscreen protects you from sunburn,” says Shari Lipner, MD, dermatologist at NewYork-Presbyterian and Weill Cornell Medicine.
You’ll notice other labels on your sunscreen that you should definitely pay attention too as well. “Ideally your sunscreen should be broad spectrum, meaning that it protects you from both ultraviolet A (UVA) and ultraviolet B (UVB) rays,” Lipner says. “Some ingredients in sunscreens that protect you from sunburn are oxybenzone, avobenzone, oxybenzone, and avobenzene.”
Which SPF is the best?
Sometimes there really can be too much of a good thing, which is why choosing the right SPF for you can be overwhelming. “The numbers following the SPF can be confusing to many patients,” Lipner says. “The SPF numbers can be misleading. SPF 30 filters 97% of the sun’s UVB rays, SPF 50 filters 98% of the sun’s UVB rays, and SPF 100 filters 99% of the suns UV rays. An SPF greater than 100 will not filter out 100% of the sun’s UV rays.”
When it comes to which sunscreen truly offers the most protection, those with a higher SPF seem to be best. “Although this is somewhat controversial, more recent evidence supports the benefit of ‘pushing’ the SPF — you might be better off with an SPF 100+ than an SPF 50+ sunscreen,” says David Lortscher, MD, board-certified dermatologist and CEO of Curology.
Of course, using a sunscreen that is an SPF 100 is extreme…and not necessary. The American Academy of Dermatology recommends that you use a sunscreen with at least an SPF of 30, since it blocks 97% of the sun’s UVB rays. “Higher SPF values (30 to 50) provide greater sunburn protection, but no sunscreen blocks 100 percent of the sun’s UVB rays,” Lortscher says.
It’s more important to apply the correct amount of sunscreen to your skin. “Sunscreen with SPF 30 is sufficient for most people when applied correctly,” Lipner says. “However, most people apply only 25 to 50% of the recommended amount of sunscreen.”
And if you plan to use a higher SPF, it’s crucial to reapply the same amount as lower SPF sunscreens. “It’s important to remember that sunscreens with a high SPF last the same amount of time as those with low SPFs,” says Dr. Lortscher. “Some people have the misconception that a high-number SPF allows you to spend more time in the sun without having to reapply your sunscreen. This is incorrect!”
What’s the best way to apply sunscreen?
Dr. Lipner shares how you should correctly apply sunscreen:
- Apply enough sunscreen to cover all exposed skin. Most adults need about 1 ounce (a full shot glass) to fully cover their skin.
- One application of sunscreen does not last the entire day. Be sure to reapply every 2 hours, after toweling off, when sweating and when swimming.
- Keep in mind that no sunscreen can filter out 100% of the sun’s UVB rays. That’s why it’s important to also wear protective clothing and seek shade.