Nicotinamide as a Skin Whitener: Evidence and Controversies

Background: Topical nicotinamide (NAM) can reduce excessive melanin deposition in cell culture, by reversibly blocking the transfer of melanosomes from melanocytes to the adjacent keratinocytes. Thus, it has been increasingly used as a whitening agent. Objective: To assess the efficacy and safety of topical nicotinamide used for the treatment of melasma and hyperpigmentation. Methods: An electronic search for topical nicotinamide was carried out on Pubmed and Medline databases to identify studies that addressed this topic as a whitening agent. And to review the primary and secondary outcomes. Results: A significant decrease in hyperpigmentation and increased skin lightness was found with the use of topical nicotinamide, compared with the vehicle In two small sample size clinical studies. Combined regimens including nicotinamide and other ingredients offer more synergistic effects than monotherapy. Conclusion: Due to the lack of sufficient evidence, the use of nicotinamide for melasma remains controversial. Extended randomized, double-blind, placebo-controlled trials with long-term follow-up periods are needed to assess the efficacy of nicotinamide as a whitening agent.