What's the Best SPF?

Navigating the Confusing World of Sunscreen

sunscreen with varying spf
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A quick stroll down the drugstore aisle or past the cosmetics counter will reveal sunscreen products with a wide range of SPF factors. If you want to prevent wrinkles and skin aging from the sun, which SPF should you choose?

SPF, or Sun Protection Factor, is a measure of sunscreen protection from UVB rays; the rays that cause sunburn and skin cancer. The number indicates how many times longer your skin can be exposed to the sun without burning. For example, an SPF of 30 means skin covered with that sunscreen can be in the sun 30 times longer without burning than it would be without any sunscreen at all.

What's the Best SPF?

Sunscreen formulas commonly contain an SPF between 15 and 60, though sun protection factors are ranked up to 90. Practically speaking, how high do you need to go? National Institutes of Health recommends using sunscreen with an SPF of 15 or higher. The American Academy of Dermatology (AAD) recommends an SPF of 30 or greater, but these are not a one-size-fits-all number. The right SPF for you depends on how your skin fares in the sun.

If you tan easily and rarely burn, a lower SPF, like SPF 30, should suffice when applied properly: every 2 hours. If you're on the other end of the spectrum and are fair-skinned and burn easily, you should absolutely use a higher SPF - nothing less than 50.

What Type of Sunscreen is Right For Me?

The best sunscreen is the one you like to use. If you like your sunscreen, you're more likely to wear it, and isn't that the point? The FDA strictly regulates sunscreen labeling, so the SPF of one brand of sunscreen does not differ from that of another.

SPF is consistent from company to company.

The reason sunscreens aren't always effective is because not enough product is applied at first and reapplied every 2 hours and after swimming or sweating. That even goes for so-called "waterproof" sunscreen. The "best" sunscreen has a minimum SPF of 15 and UVA or broad-spectrum protection.

Sunscreen Is Only One Part

Both National Institutes of Health and the AAD warn that sunscreen is only part of the sun protection story. People are cautioned to use clothing to block the sun’s rays, including long sleeves, pants, hats and sunglasses, even on cloudy days.

Generous application of sunscreen might be more important than a high SPF factor. The AAD estimates that people typically apply only one quarter to half of the amount of sunscreen they should apply: optimally about an ounce - 30 millimeters or 2 tablespoons - for the exposed skin of an average body.

In order to use sunscreen to prevent skin cancer and early skin aging, the product needs to protect against UVA  and have a minimum SPF of 15. Otherwise, it's only preventing sunburn.


Sun Exposure. US National Institutes of Health Medline Public Information Sheet. Accessed August 28, 2012.

Sunscreens. American Academy of Dermatology Public Information Sheet. Accessed August 28, 2012.

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