CAM PoliticsSaw Palmetto

The STEP report on saw palmetto safety

STEP stands for “Saw palmetto for Treatment of Enlarged Prostates.”

Saw palmetto is among the top 10 herbal/supplements. Men with lower-urinary tract symptoms commonly use it.

First, the details.

  • 225 men with moderate-to-severe symptoms of benign prostatic hyperplasia were studied.
  • Standardized extract of the saw palmetto berry (160 mg twice daily) was compared to placebo over 1 year.
  • Adverse events, sexual function, and laboratory tests of blood and urine were monitored.

And, the results.

  • There were no significant differences between the saw palmetto and placebo in the risk of having at least one serious side effect (5% vs 10%, respectively).
  • Non-serious symptomatic side effects were 35% vs 30% with saw palmetto and placebo, respectively.
  • There were few significant differences between groups in sexual functioning or in most laboratory values.
  • There were statistically significant but small differences in total bilirubin, potassium, and the incidence of sugar in the urine (0% with saw palmetto vs 3.7% with placebo).

The bottom line?
The authors concluded there was “no evidence for serious toxicity of saw palmetto…; however, these data do not rule out potential rare adverse effects.”

Aside from the importance of defining the safety of supplements, the results have political implications. Almost 2 years ago, the Danish Ministry for Family and Consumer Affairs prohibited food supplements containing saw palmetto because, in part, of concerns about a lack of safety information during long-term use. has reviewed the uses and safety of saw palmetto.

4/23/08 19:45 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.