Simply put, dihydroxyacetone is the active ingredient used to make self-tanners work. Discovered to have skin darkening properties in the 1920s by a German scientist, DHA is typically derived from plant sources, such as beets or sugar cane.
DHA works by interacting with the amino acids of your dead skin cells, resulting in a brownish-tan hue. The color sticks around for about three to ten days, depending on how long it takes for your skin cells to shed.
The first commercial self-tanning product was released in 1960 from Coppertone, called Quick Tan or QT. The biggest problem with early formulations? Orange, streaky results. Nowadays you can get your own dose of DHA in many sun-free ways: creams, sprays, wipes, and even mousses — streak and orange free.