Saw palmetto is native to the southeastern United States, where its berries were traditionally used by Native American peoples before being adopted into 19th-century American herbal and eclectic medicine, particularly for urinary and reproductive complaints. It became one of the most widely used herbal supplements globally, specifically marketed for benign prostatic hyperplasia (BPH).
Saw palmetto's evidence base is genuinely instructive precisely because of how it has evolved: earlier positive findings gave way to considerably more rigorous, larger trials reaching different conclusions.
Saw palmetto has real earlier evidence suggesting benefit for BPH symptoms. An earlier meta-analysis found saw palmetto extract provided significant improvement in peak urinary flow rate and reduced nighttime urination compared to placebo, and individual trials found efficacy comparable to standard pharmaceutical treatments like finasteride.
However, the most rigorous, larger, and more recent evidence points differently. A year-long randomized controlled trial published in the New England Journal of Medicine found saw palmetto "was not superior to placebo," with notably narrow confidence intervals around this null finding. A comprehensive 2012 Cochrane review, examining 5,666 men including double and triple standard doses, similarly found no improvement in urinary flow or prostate size compared to placebo. Given this genuine, unresolved tension where the more recent and rigorous evidence leans negative, "Limited-Moderate" is the honest rating.
Berries dried and prepared as standardized lipid extract capsules, tea, or tincture.