UC Irvine

Saw palmetto (SP), a botanical extract with antiandrogenic properties, has gained commercial popularity for its purported benefits on hair regrowth. To summarize published evidence on the efficacy, safety, and tolerability of supplements containing SP in the treatment of alopecia, we conducted a PubMed, Google Scholar, and Cochrane database search using the following terms: (saw palmetto and hair loss), (saw palmetto and androgenetic alopecia), and (saw palmetto and natural supplement and alopecia). Five randomized clinical trials (RCTs) and 2 prospective cohort studies demonstrated positive effects of topical and oral supplements containing SP (100-320 mg) among patients with androgenetic alopecia (AGA) and telogen effluvium. Sixty percent improvement in overall hair quality, 27% improvement in total haircount, increased hair density in 83.3% of patients, and stabilized disease progression among 52% were noted with use of various topical and oral SP-containing supplements. SP was well tolerated and not associated with serious adverse events in alopecia patients. Although robust high-quality data are lacking, supplements containing SP may be a treatment option for patients with AGA, telogen effluvium, and self-perceived hair thinning. Further large-scale RCTs focusing on the sole contribution of SP to hair growth outcomes are needed to confirm efficacy and determine long-term adverse events.