RESUMO
BACKGROUND: Rice bran extracts (RB) derived from Oryza sativa are part of cultural skin and hair care practices in Asia. Given the knowledge gap regarding clinical efficacy, marketplace availability, and safety, the growing popularity of nutraceuticals calls for better clinician awareness and scientific understanding of their applications and limitations. OBJECTIVE: To review available scientific evidence regarding therapeutic efficacy, safety, and consumer availability of RB on hair health. MATERIALS AND METHODS: A primary literature search was conducted using PubMed to identify articles on RB and hair growth in May 2021. A limited market analysis of rice-derivative-containing hair products was also conducted on Amazon.com. RESULTS: 10 studies were analyzed: six regarding the efficacy of RB for hair growth, and four analyzing the safety profile of RB. Topically applied RB increases expression of growth factors and molecular signals which promote cell proliferation in the anagen phase including β-catenin, while inhibiting enzymes responsible for propagating anagen to catagen/telogen transition including TGFβ and Type I 5α-reductase. RB is non-genotoxic, non-cytotoxic, and appropriate for human use in cosmetics. The Amazon.com search yielded 119 rice-containing hair products, reflecting their over-the-counter popularity. CONCLUSIONS: Current literature is promising for RB promoting hair growth given its ability to increase expression of growth factors and molecular signals associated with maintaining anagen phase, decreasing inflammation, inhibiting 5α-reductase, and promoting melanogenesis. J Drugs Dermatol. 2022;21(2):177-185. doi:10.36849/JDD.6345.
