Making Sense of Sunscreens

Dermatologists weigh in on which sunscreen ingredients you should look for to best protect your skin.

- Joanna Cosgrove

With about 3.5 million cases diagnosed each year in the U.S., skin cancer is the most common of all cancers, according to the American Cancer Society. A big risk factor is too much exposure to ultraviolet (UV) radiation from sunlight. That’s why dermatologists encourage the daily, liberal use of water proof sunscreens and lip balms that deliver broad-spectrum protection against both UVA and UVB rays and offer a sun protection factor (SPF) of 30 or higher.

There is a dizzying variety of spray, lotion, and stick sun screen options available, but your first consideration should be what’s listed on the ingredient panel. 

For starters, the higher the SPF number, the more sunburn-inducing UVB light will be filtered out—but not UVA. According to the Environmental Working Group, “A sunscreen lotion’s SPF rating has little to do with the product’s ability to shield the skin from UVA rays. As a result of the FDA’s restrictions on ingredients and concentrations, U.S. sunscreens offer farless protection against UVA than UVB, particularly those products with the highest SPF.”

SPF numbers can be misleading too. For example, an SPF 30 blocks roughly 93 percent of sunburn rays, whereas an SPF of 50 blocks about 98 percent.