Are self-tanning lotions safe to use? —T.V., Winona Lake, Ind.

They appear to be. All self-tanners approved by the Food and Drug Administration use the same color-producing chemical, a substance called dihydroxyacetone (DHA) that reacts with proteins in the outermost layer of your skin to create a brownish pigment called melanoidin. The sunless tan usually lasts two to five days, wearing off as you naturally shed the darkened outer skin cells.

While a few test-tube studies have suggested that DHA might cause cell damage, we could find no human studies examining that risk. But it’s been used in the U.S. for more than 40 years with no major ill effects reported. And the FDA allows DHA in cosmetics only if, as in lotions, they’re not likely to enter the body. (The spray “mists” available in tanning salons technically aren’t FDA-approved since they can come in contact with your eyes, lips, and nose.)

Read more on how to get a tan without the sun, and see our sunless tanning product Ratings  (subscribers only). And before you go out in the sun this weekend, take a look at our new sunscreen survey and Ratings (subscribers only).