Effectiveness and Safety of Saw Palmetto as a Dietary Supplement

Abstract

Background: Serenoa repens (saw palmetto) is a widely used herbal supplement for men’s health conditions such as benign prostatic hyperplasia (BPH), androgenetic alopecia, and chronic pelvic pain. However, evidence regarding its effectiveness and safety remains inconsistent. Objectives: This review evaluated the efficacy and safety of oral saw palmetto supplements in adults, focusing on randomized controlled trials (RCTs). Methods: MEDLINE, Embase, CENTRAL, and PubMed were searched for RCTs of oral saw palmetto monotherapy. Data extraction and risk of bias assessment were performed independently. Primary outcomes included the International Prostate Symptom Score (IPSS), urinary flow rate, quality of life, and adverse events. Secondary outcomes were prostate-specific antigen (PSA), adherence, and hormonal biomarkers. Results: Eleven RCTs with 2,907 men were analysed. Asian trials reported IPSS reductions of 6-8 points compared with 3-4 points for placebo, alongside urinary flow improvements of +2-3 mL/s. Early European studies using standardized extracts such as Permixon also suggested benefits. By contrast, large North American multicenter trials, including CAMUS, found no significant differences, with both groups improving by about 2 IPSS points and showing minimal changes in flow. PSA levels and prostate volume were generally unchanged, while quality-of-life outcomes reflected symptom trends. Adverse events were mild, transient, and not dose-dependent, even at doses up to 960 mg/day. Conclusion: Saw palmetto appears safe and well tolerated. Some standardized extracts may provide modest benefits, but overall clinical effectiveness remains uncertain. Future research should prioritize standardized formulations, longer follow-up, and more diverse populations.