Sunless tanners work without sunlight to safely combine with the natural amino acids on the surface of the skin. The active ingredient in virtually all sunless tanning formulas is DHA (Dihydroxyacetone.) DHA has undergone decades of dermatological testing and is proven safe. Its the way to a gorgeous tan without spending a minute under the harmful sun. When DHA is applied to the skin, it reacts with the amino acids in the skin to produce a tan, much like how the sun does, but without UVA and UVB damage to the skin.