Is Sunless Tanning Safe? In a word, no. According to Isabel Blumberg, M.D., a clinical instructor in the department of obstetrics and gynecology at the Mount Sinai Medical Center in New York, the active ingredient in DIY self-tanner and professional spray tans is dihydroxyacetone (DHA).
“The long-term effects of DHA have yet to be tested,” says Blumberg. However, tanning products are applied to such a large area of skin that it’s best to avoid them—and the potential side effects to you and your developing baby.