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Saw Palmetto


Saw palmetto is a small tree that grows in North and Central America. The fruit from the tree has been used to ease urinary symptoms. Saw palmetto fruit can be eaten plain, dried then eaten, or made into tea or juice. It can also be taken as a pill, powder, or extract.


320 milligrams 1 to 2 times daily

What Research Shows

May Be Effective

  • Male androgenic alopecia —may increase hair growth B1

May Not Be Effective

  • Benign Prostatic Hyperplasia (BPH) A1-A7

Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.

Safety Notes

It is likely safe for most adults to take saw palmetto in small doses for a short time. Not enough studies have been done to say whether it is safe to use for a long period. Saw palmetto may not be safe for women who are pregnant or breastfeeding.


Talk to your doctor about any supplements or therapy you would like to use. Some can interfere with treatment or make conditions worse such as:

  • People taking blood thinners should talk to their doctor before taking saw palmetto. It may increase the risk of bleeding.C1, C2


A. Benign Prostatic Hyperplasia

A1. Cai T, Mazzoli S, et al. Serenoa repens associated with Urtica dioica (ProstaMEV) and curcumin and quercitin (FlogMEV) extracts can improve the efficacy of prulifloxacin in bacterial prostatitis patients: results from a prospective randomised study. Int J Antimicrob Agents. 2009 Jun;33(6):549-553.

A2. Morgia G, Mucciardi G, et al. Treatment of chronic prostatitis/chronic pelvic pain syndrome category IIIA with Serenoa repens plus selenium and lycopene (Profluss) versus S. repens alone: an Italian randomized multicenter-controlled study. Urol Int. 2010;84(4):400-406.

A3. Barry MJ, Meleth S, et al. Effect of increasing doses of saw palmetto extract on lower urinary tract symptoms: a randomized trial. JAMA. 2011 Sep 28;306(12):1344-1351.

A4. Tacklind J, Macdonald R, et al. Serenoa repens for benign prostatic hyperplasia. Cochrane Database Syst Rev. 2012 Dec 12;12:CD001423.

A5. MacDonald R, Tacklind JW, et al. Serenoa repens monotherapy for benign prostatic hyperplasia (BPH): an updated Cochrane systematic review. BJU Int. 2012 Jun;109(12):1756-1761.

A6. Argirovíc A, Argirovíc D, et al. Does the addition of Serenoa repens to tamsulosin improve its therapeutic efficacy in benign prostatic hyperplasia? Vojnosanit Pregl. 2013;70(12):1091-1096.

A7. Coulson S, Rao A, et al. A phase II randomised double-blind placebo-controlled clinical trial investigating the efficacy and safety of ProstateEZE Max: a herbal medicine preparation for the management of symptoms of benign prostatic hypertrophy. Complement Ther Med. 2013 Jun;21(3):172-179.

B. Male Androgenic Alopecia

B1. Rossi A, Mari E, et al. Comparitive effectiveness of finasteride vs Serenoa repens in male androgenetic alopecia: a two-year study. Int J Immunopathol Pharmacol. 2012 Oct-Dec;25(4):1167-1173.

C. Safety

C1. Cheema P, El-Mefty O, et al. Intraoperative haemorrhage associated with the use of extract of Saw Palmetto herb: a case report and review of literature. J Intern Med. 2001 Aug;250(2):167-169.

C2. Milić N, Milosević N, et al. Warfarin interactions with medicinal herbs. Nat Prod Commun. 2014 Aug;9(8):1211-1216.

Last reviewed July 2019 by EBSCO NAT Review Board Eric Hurwitz, DC  Last Updated: 3/30/2020