Since sunscreens come in so many different SPFs (ranging from around 2 to 100), is the higher number always better? Is an SPF that is too high actually bad for you, and what SPF do you really need?

Why I regularly use sunscreens that are at least SPF 30
For every day use, I always choose sunscreens that are at least SPF 30, and my favorite sunscreen happens to have an SPF 55. It takes a lot of sunscreen to actually achieve the stated level on the tube! For some reason I always thought you needed a teaspoon of sunscreen for your face, but it turns out you only need 1/4 or 1/3 of a teaspoon to adequately cover your face. A shot glass of sunscreen is what you need to cover your whole body.

As vigilant as I am about sunscreen, I find it hard to put an entire third of a teaspoon of sunscreen on my face. No matter how great the sunscreen, it starts to look thick and unnatural when you have a super thick coat of it on. It also gets expensive! My other fear is that when I put on foundation over the sunscreen, I worry that some of the sunscreen ends up back on my hands. Also, if I’m not going to be out in the sun, I don’t want to have to reapply my sunscreen every few hours, since I have on makeup. I’m sure some of the sunscreen wears off as the day goes on. If I do go to the beach or pool, I stay in the shade, and slather on the third of a teaspoon on my face, and reapply at least every two hours, and right after being in the water.

It’s estimated that people only apply about half as much sunscreen as they should. So that SPF 30 is more like an SPF 15. That SPF 15 is inadequate sun protection if you don’t use enough. Paula Begoun has a sun essentials/sunscreen FAQ that has lots of useful information.

Sunscreen does not offer 100% sun protection
Even the best sunscreen is not going to offer 100% sun protection. With the correct amount, an SPF 30 offers about 97% UVB sun protection, while an SPF 15 offers about 95% protection. Personally I want all the protection I can get because I still notice freckles appear when I’m out in the hot sun, and I sometimes get a slight tan, even when I slather on the recommended amount of sunscreen.

Is a high SPF dangerous?
An SPF higher than 30 is still only going to provide about 97% UVB protection. The higher number just means you can stay out longer in the sun without getting burned. In Paula Begoun’s book Don’t Go To The Cosmetics Counter Without Me, when reviewing Neutrogena Dry-Touch Sunblock SPF 70, she does state that higher SPF sunscreens put more sunscreen active ingredients on your skin, which isn’t necessarily a good thing.

How I choose sunscreens
Primarily I look for sunscreens with at least 10% Zinc Oxide and an SPF 30+. I have 20 more posts I’ve written about sunscreen that go into more detail about ingredients. I also personally like sunscreens that are waterproof in the summer, so that they don’t sweat off. I am not afraid of higher SPF sunscreens, but I’m also happy with sunscreens in the 30-55 range for every day use.