How do sunless tanning products work?

Sunless tanning products, also called self-tanners, can give your skin a tanned look without exposing it to harmful ultraviolet (UV) rays. Sunless tanning products are commonly sold as lotions, creams and sprays you apply to your skin. Professional spray-on tanning also is available.

The active ingredient in most sunless tanning products is the color additive dihydroxyacetone (DHA). When applied, dihydroxyacetone reacts with dead cells in the skin's surface layer to temporarily darken the skin and simulate a tan. The coloring typically wears off after a few days.