A review of dihydroxyacetone.
J Am Acad Dermatol
Introduction: Recently the sunless tanning industry has experienced rapid growth due to public education on the dangers of ultraviolet radiation (UVR) on the skin and improvements in sunless tanning products. Dihydroxyacetone (DHA) is a 3-carbon sugar approved as a color additive by the Food and Drug Administration (FDA) and found in sunless tanning products for external use. It reacts with amino acids in the stratum corneum to impart a tanned color to the skin. Formulations typically contain 3% to 5% DHA and can be sprayed on at home or applied as a cream or lotion. DHA has been used in tanning booths and airbrushed by technicians, which is beyond the scope of approval for the color additive. We review the literature on DHA including the published safety data, the current regulations on its use, its clinical utility, and the possible photoprotective properties of this product.
Methods and results: We reviewed published in vivo and in vitro studies where DHA had been used. Clinical safety investigations were few in number with limited sample sizes. DHA is approved by the FDA as a color additive in sunless tanners for external application, not including the mucous membranes of the lips. The FDA cautions tanning booth customers against unwanted DHA exposure, recommending that customers shield their eyes, lips, and mucous membranes and refrain from ingestion or inhalation of DHA. While the FDA regulates spray tanning products, state and local health authorities regulate the tanning booth. Despite reports of very modest photoprotective effects (SPF 1-3), DHA is not a sunscreen, and as such, it cannot provide any protection from exposure to the sun’s UVR. Literature reports indicate that DHA has been used as camouflage for vitiligo patients and as an adjunct to psoralen-ultraviolet A therapy in psoriasis. While not indicated for the treatment of fungal infections, DHA has also demonstrated fungicidal properties. Reported side-effects included xanthotrichia and allergic contact dermatitis.
Conclusion: DHA is an FDA-approved color additive used in sunless tanners. The literature shows that it has a good safety profile, with no to minimal photoprotective property, as would be expected, since DHA is not a sunscreen ingredient. With its wide-spread use, additional studies on its safety, especially on its potential effects upon inhalation, are warranted.