Dihydroxyacetone (DHA) is used in cosmetic products to darken the skin chemically, providing sunless tanning. It is considered nontoxic and noncarcinogenic.
Previously, studies have shown that DHA induces concentration-dependent photoprotection against UV-A and visible light.1 Commercialproducts containing DHA are often labeled as having no sun protection. However, our laboratory has shown that DHA absorbs UV-B and delays photocarcinogenesisin hairless mice.2 We therefore examined whether DHA offers any protection against erythema in humans.