

Dr. Lara Butler, MD
Board Certified Dermatologist
So the American Academy of Dermatology recommends sunscreens be broad-spectrum, UVA/UVB coverage, that is an SPF of 30 or higher. And what that means, SPF of 30, is that it blocks about 97% of the sun's UVB rays. And UVB is what's responsible for burns and skin cancer. When you get up to an SPF of 50, you're blocking about 98%. And when you're at an SPF of 100, you're blocking 99%. So certainly that higher SPF is going to give you a little better blockage. But what we found is that these higher SPFs of 100, give people a false sense of security. And then they end up in the sun longer, and then they do get more sunburns. So what's important to know, regardless of the SPF, you need to reapply every 2 hours. If you have an SPF of 100, that doesn't mean it will last longer. Every 2 hours, you need to reapply an SPF 30, an SPF 50, or an SPF 100. So you know, pick your whatever sunscreen you're actually going to use, whether it's a lower number or a higher number at least 30 or higher though, and just reapply every 2 hours.