Scientists Are Finding Out Just How Toxic Your Stuff Is

If you are newly suspicious about the safety of the products in your medicine cabinet, there’s a good chance you have Valisure, a tiny laboratory in New Haven, Conn., to thank. Or blame.

Tucked away in an unassuming office park, Valisure’s team of about a dozen scientists has over the past five years detected potentially cancer-causing chemicals in widely used medications, hand sanitizers, sunscreens, antiperspirant body sprays, dry shampoos, and—most recently—acne treatments. When...