The effect of increasing doses of saw palmetto fruit extract on serum prostate specific antigen: analysis of the CAMUS randomized trial

J Urol. 2013 Feb;189(2):486-92. doi: 10.1016/j.juro.2012.09.037. Epub 2012 Dec 14.


Purpose: Saw palmetto extracts are used to treat lower urinary tract symptoms in men despite level I evidence that saw palmetto is ineffective in reducing these lower urinary tract symptoms. We determined whether higher doses of saw palmetto as studied in the CAMUS (Complementary and Alternative Medicine for Urologic Symptoms) trial affect serum prostate specific antigen levels.

Materials and methods: The CAMUS trial was a randomized, placebo controlled, double-blind, multicenter, North American trial conducted between June 5, 2008 and October 10, 2012, in which 369 men older than 45 years with an AUA symptom score of 8 to 24 were randomly assigned to placebo or dose escalation of saw palmetto, which consisted of 320 mg for the first 24 weeks, 640 mg for the next 24 weeks and 960 mg for the last 24 weeks of this 72-week trial. Serum prostate specific antigen levels were obtained at baseline and at weeks 24, 48 and 72, and were compared between treatment groups using the pooled t test and Fisher's exact test.

Results: Serum prostate specific antigen was similar at baseline for the placebo (mean ± SD 1.93 ± 1.59 ng/ml) and saw palmetto groups (2.20 ± 1.95, p = 0.16). Changes in prostate specific antigen during the study were similar, with a mean change in the placebo group of 0.16 ± 1.08 ng/ml and 0.23 ± 0.83 ng/ml in the saw palmetto group (p = 0.50). In addition, no differential effect on serum prostate specific antigen was observed between treatment arms when the groups were stratified by baseline prostate specific antigen.

Conclusions: Saw palmetto extract does not affect serum prostate specific antigen more than placebo, even at relatively high doses.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Androgen Antagonists / administration & dosage*
  • Androgen Antagonists / therapeutic use
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Humans
  • Male
  • Middle Aged
  • Plant Extracts / administration & dosage*
  • Plant Extracts / therapeutic use
  • Prostate-Specific Antigen / blood*
  • Prostatic Hyperplasia / blood*
  • Prostatic Hyperplasia / drug therapy*
  • Serenoa


  • Androgen Antagonists
  • Plant Extracts
  • Prostate-Specific Antigen
  • saw palmetto extract