Clinical Use and Safety of Self-Tanner (Topical Dihydroxyacetone) in Dermatology: A Systematic Review

BACKGROUND: Dihydroxyacetone (DHA) is the key ingredient in commercially available self-tanners, which are a popular alternative to sun-tanning. OBJECTIVES: This systematic review (PROSPERO: CRD42024558929) presents safety and clinical data about topical DHA in human and animal models since its discovery, to guide dermatologists in counseling their patients about DHA, its possible use in cutaneous diseases, and sun protection. METHODS: This systematic review includes 16 studies retrieved in July 2023 from Embase, Medline, Cochrane, and Web of Science, following the preferred reporting items for systematic reviews and meta-analyses guidelines, and from searches of retrieved articles' bibliographies. All studies were critically appraised using Cochrane's Risk of Bias in Non-Randomized Studies of Interventions and the Risk of Bias Tool for Randomized Trials (second version) tools. RESULTS: Murine model data suggest DHA may provide minimal photoprotection, insufficient to replace sunscreen, and may delay ultraviolet radiation-linked tumor development. Patients with erythropoietic protoporphyria (EPP) and vitiligo may benefit from DHA. No link has been established between DHA and clinically relevant vitamin deficiency and contact dermatitis. Concerns remain about cutaneous free-radical formation and product absorption. DHA's use in psoralen-UVA therapy does not warrant further development. DHA's role in altering the evaluation of melanocytic lesions with dermoscopy is minor. CONCLUSIONS: DHA may have some use in patients with vitiligo and EPP. No studies demonstrated harm related to DHA use, though most studies were low-quality, conducted on a few humans or animals, occasionally with product concentrations over the threshold permitted by the European Commission. Unresolved safety concerns about free-radical formation require high-quality research to clarify DHA's long-term health impacts.