The U.S. Food and Drug Administration last week approved a new sunscreen ingredient used overseas for years but never before in the United States to block a type of radiation that penetrates deeper into the skin.
L'Oreal's Mexoryl protects against a broader range of the sun's UVA rays, which can penetrate the skin's lower layer, or dermis. UVB rays from the sun damage only the skin's outer layer, the epidermis.
Though UVB is associated with sunburn, experts believe UVA plays a bigger role in skin cancers and wrinkles.
Mexoryl will be available without a prescription in a product called Anthelios SX, which also contains two older sunscreens known as avobenzone and octocrylene.
Known generically as ecamsule, Mexoryl has been sold in Europe and Canada since 1993. Dermatologists have praised Mexoryl's effectiveness at blocking UVA rays, and some Americans have sought it out through the Internet and other foreign sources.
"It's an excellent UVA blocker with a decent track record in Europe and Canada.... I think this is an important addition to what we have available to us," said Dr. Stephen P. Stone, president of the American Academy of Dermatology and professor of clinical medicine at Southern Illinois University School of Medicine.
L'Oreal said Anthelios SX would be marketed as a daily moisturizing cream starting in the fall. The company said it planned to introduce other daily moisturizers and sunscreens containing Mexoryl in the future. The FDA said it recommended that consumers use sunscreens to protect themselves but also limit time in the sun and wear protective clothing.