Remember thalidomide?

In the 1950s and early 60s the drug was given to pregnant women as a cure for nausea. Unfortunately, it caused severe birth defects in their children, most notably truncated or missing limbs. Because of the dire consequences of this drug, in 1962 the government enacted the Kefauver-Harris amendment to the Federal Food, Drug and Cosmetic Act, which requires drug makers to satisfy the F.D.A. that their products are safe and effective before they go on sale. (I was kind of blown away by the fact that, before 1962, drugs could be sold without any data to support their claims of efficacy.)

Anyhow, the more than 100,000 drugs already on the market needed to be reviewed. To streamline the process, if the drugs’ components had been deemed to be safe and effective, they could be used under specific conditions without further review. But about a third of the drugs have still not undergone the final review process. That is, hundreds of over-the-counter drugs have not yet been determined to be safe and effective. Sunscreens are one of these.

Beginning in 1997, scientists discovered that oxybenzone, the chemical that filters out UV rays, does not stay on the surface of the skin but is absorbed. It has been found in urine and breast milk. (The CDC found that 97 percent of sunscreen-users’ urine samples contained the chemical.) At the same time, there’s never been any indication that sunscreen chemicals are harmful to humans, and evidence has shown that sunscreen can prevent skin cancer. Still, because sunscreens have not been studied (too many variables!), we don’t know about long-term effects—whether sunscreen use, for example, plays a role in infertility or anything else.

I use sunscreen on my nose sometimes to prevent it from getting any redder than it already is. I’ve had plenty of skin cancers and am plagued by actinic keratosis, which are supposedly pre-cancerous (but have never turned into cancer). Even so, I rarely use sunscreen, mostly because of the bother. My husband has never used it and has never had skin cancer or actinic keratosis. Perhaps a study is called for.

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