The active ingredient in sunless tanners is DHA (dihydroxy acetone). DHA is approved by the food and drug administration for use in sunless tanning products. DHA is naturally derived from sugar. It synthesizes with the skin’s proteins and amino acids in the outermost layer (epidermis) of the skin, working with your own natural pigments to produce a safe, natural looking tan.
DHA reacts with the dead skin cells, therefore, as those skin cells slough off, so does your tan. Each person has a unique skin cell cycle, affected by numerous factors including, but not limited to, hormones, genetics, age, medications, the environment and products used topically on the skin.
DHA was discovered 70 years ago. Since this time, there have been numerous studies to show that DHA applied topically to the skin has no reactions or adverse affects.