Something strange is happening in the sunscreen aisle. Shelves that had been stocked with bottles claiming an SPF, or a sun protection factor, of 30 now trumpet SPFs of 55, 70, even "110+." This not-so-subtle escalation often comes with corollary pricing. Higher SPFs frequently cost more, but are they worth it?
Many dermatologists don't think so.
"Once you get to SPF 50, it's really getting silly," said Boston dermatologist, James Spencer. "SPF refers to multiples of how much longer it takes the skin to burn," but it isn't a linear progression.
An SPF of 30 doesn't offer twice as much protection as an SPF of 15, for example. An SPF 15 blocks 94% of UVB rays, SPF 30 blocks 97%, and SPF 45 blocks 98%.
Spencer recommends sunscreens with an SPF of 30, as does the American Academy of Dermatology, "because we know you're not going to put enough on."