04/02/2026
Prior clinical work on saw palmetto (Serenoa repens), particularly the liposterolic extract, suggests modest activity in androgenetic alopecia (genetically driven male pattern hair loss), though the evidence base remains modest and mixed. A 2002 double blind, placebo-controlled pilot trial of oral liposterolic extract (combined with beta-sitosterol) reported investigator-rated improvement in about 60% of treated men, but the sample size was very small. A 24-month open-label comparative study found oral saw palmetto liposterolic extract (SPLE, 320 mg/day) improved hair growth in roughly 38% of men versus 68% with finasteride. Topical studies have demonstrated increases in hair counts and thickness, though many used combination products and lacked placebo controls, limiting attribution specifically to saw palmetto. More recent nutraceutical trials that include the herb as part of multi-ingredient formulas also report improvements in hair density and shedding, but again cannot isolate its independent contribution.
Hence a newly published RCT is a welcome addition to the evidence base. This was a planned 6-month double blind RCT (2:1 allocation to active treatment; n=60) evaluating an oral proprietary SPLE (160 mg daily) in men and women with self-perceived thinning hair, with interim results reported at 90 days. At three months, the active group (n=40) demonstrated statistically significant increases in anterior and posterior terminal hair counts (approximately +11 to +12 hairs/cm²), increases in total hair counts in both regions, and reduced hair shedding compared to baseline and placebo. The placebo group (n=20) showed minimal change. These overall gains translated to roughly 8 to 12% relative increases in hair density over 90 days, indicating a moderate but measurable improvement. In a predefined subgroup of nonchildbearing-age women (n=15 within the active arm), anterior terminal hair counts increased by about 7 to 8%, anterior total hair counts rose by approximately 11%, vellus hair counts increased, and shedding decreased by over 70%, though this subgroup lacked a matched placebo comparator. The dose used in this trial (160 mg/day of SPLE) is notably half the conventional 320 mg/day commonly used in benign prostatic hyperplasia studies.
Compared with earlier studies, the current trial strengthens the evidence base by using a randomised, double blind, placebo-controlled design with objective trichoscopic hair counts in both men and women, though the effect size remains broadly consistent with the moderate improvements reported in prior trials.
While saw palmetto is often positioned as a 5-α-reductase inhibitor (like finasteride), its clinical effects on hair growth are likely better explained by broader microenvironmental modulation. Liposterolic extracts contain fatty acids and phytosterols that appear to reduce local inflammation, influence prostaglandin signaling, modulate androgen receptor activity rather than simply suppress dihydrotestosterone, alter scalp lipid and sebaceous dynamics, and generally improve the perifollicular environment.
For more information see: https://pubmed.ncbi.nlm.nih.gov/41319217/
