The best sunscreen is one that you'll use generously and according to label directions. Here's help understanding sunscreen ingredients, types of sunscreen and more.
Focus on the big picture when it comes to sun safety. For example:
There are two types of UV light that can harm your skin — UVA and UVB. A broad-spectrum, or full-spectrum, sunscreen protects you from both.
UVA rays can prematurely age your skin, causing wrinkling and age spots. UVB rays can burn your skin. Too much exposure to UVA or UVB rays can cause skin cancer. The best sunscreen offers protection from all UV light.
SPF stands for sun protection factor, a measure of how well sunscreen protects against UVB rays. (UVA protection isn't rated.) Manufacturers calculate SPF based on how long it takes to sunburn skin that's been treated with the sunscreen as compared to skin with no sunscreen.
When applied correctly, a sunscreen with an SPF of 30 will provide slightly more protection from UVB rays than does a sunscreen with an SPF of 15. But the SPF 30 product isn't twice as protective as the SPF 15 product. Sunscreens with SPFs greater than 50 provide only a small increase in UV protection.
Also, sunscreen is often not applied thoroughly or thickly enough, and it can be washed off during swimming or sweating. As a result, even the best sunscreen might be less effective than the SPF number suggests.
Rather than looking at a sunscreen's SPF, choose a broad-spectrum sunscreen.