When you wash your hair, clean or moisturize your skin, polish your nails, or put on makeup, deodorant or sunscreen, do you ever think about whether the product you’re using may do more harm than good?

Maybe you should. Thanks to a lack of federal regulations, the watchword for consumers of cosmetics and personal care products should be caveat emptor: Let the buyer beware.

To be sure, these products are not nearly as worrisome as drugs, which require extensive testing and premarket approval by the Food and Drug Administration. Still, disasters can and sometimes do occur from the use of cosmetics and personal care products, and the government is powerless to act until a slew of consumer complaints raise a red flag about a product.

In a recent editorial in JAMA Internal Medicine, Dr. Robert M. Califf, who served as F.D.A. chief under President Obama, noted, “The cosmetic industry remains largely self-regulated. History has repeatedly shown that when there is insufficient regulatory oversight, a few unscrupulous people or companies will exploit the vulnerable public for profit.”