How Sunless Tanning Works
Dihydroxyacetone (DHA) is the active ingredient in just about every sunless tanning product. What makes each product different is the amount of DHA used and the other “stuff” that is added to the solution. More on this later.
DHA is a colorless sugar that interacts with the outer layer of skin, the epidermis, causing a color change. Your skin exfoliates all day every day. In fact, every 35 to 45 days, you have an entirely new epidermis. That is why all sunless tanners will eventually fade. Million Dollar Tan is so well made that if the skin did not exfoliate, your tan would last forever. But since the skin will always exfoliate, we will have to continue spray tanning about once a week.