As far as "anti-aging" goes, your best bet is sunscreen. (Let this sink in. Sunscreen is worth every penny.) But all those options! The ever-increasing numerals! What's the difference between an SPF 50 foundation and an SPF 100 one, anyway?
As it turns out, about 1 percent.
The numbers that describe sun-protection factors don't work like any normal person would imagine. Thirty is not twice as protective as 15: A product with SPF 15 blocks 94 percent of UVB rays, while SPF 30 blocks 97 percent. And as you move up the SPF ladder, the difference becomes even more negligible. An SPF 50 foundation blocks 98 percent vs. about 99 percent for SPF 100.
Most experts scoff at anything above 50. To protect your skin from the sun, SPF 15 is sufficient, and SPF 30 is a reasonable upgrade. Just be sure you apply the product liberally or else you won't get the full protection.
Next: When even SPF 15 is pointless.