The Ability of Dihydroxyactone from Self-Tanning Products to React with Stratum Corneum

Artificial tanning products are used to mimic the darkening effect ultraviolet radiation has on the skin, avoiding potential harms such as skin cancer. However, there are varying answers on how dihydroxyacetone (DHA), the key ingredient in self-tanning products, affects the skin. The dark pigment self-tan produces is the result of brown melanoidins produced by a non-enzymatic Maillard reaction between DHA and amino acids in the outer layer of the skin. Some research suggests that this reaction may risk DNA damage and cell death. For example, Shayan Owji at the Transitional Residency Program at John Peter Smith Hospital analyzed a multitude of pre-existing studies on DHA in STPs. After reviewing multiple credible sources, they conclude that concentrations of DHA ranging from 1% to 15% produce DNA damage and “induce significant cytotoxicity, even low millimolar, nonlethal concentrations can alter the function of keratinocytes…”(Owji et al., 2023, para. 1). However, according to The Skin Cancer Foundation, “the resulting reaction causes browning, but unlike the reaction caused by UV rays, it involves only the outermost, dead cell layer of the skin”(The Skin Cancer Foundation, 2019). Therefore, the true effects of self-tanning products on the epidermis are unclear. This project investigates the ability of DHA to react with the outermost layer of the skin, excluding cells deeper than the stratum corneum, by applying three different concentrations of DHA to porcine skin. A “light” tanning solution with 6% DHA, a “medium” solution with 9% DHA, and a “dark” solution with 12% DHA.