Saw Palmetto

ByLaura Shane-McWhorter, PharmD, University of Utah College of Pharmacy
Reviewed/Revised Mar 2024
VIEW PROFESSIONAL VERSION

Saw palmetto is also available as tablets, capsules, and a liquid extract.

(See also Overview of Dietary Supplements.)

Claims for Saw Palmetto

Saw palmetto counteracts the effects of testosterone. Many men take saw palmetto to treat benign enlargement of the prostate gland (benign prostatic hyperplasia). Additional claims are that saw palmetto increases sperm production, breast size, and sexual vigor, and has anti-inflammatory and anticancer effects. It has also been used to increase scalp hair growth in people who have male pattern baldness.

Evidence for Saw Palmetto

There is no scientific evidence to suggest that saw palmetto reverses benign prostatic hyperplasia. 

Although well-designed studies did not show any benefit from saw palmetto for symptoms of an enlarged prostate gland, such as frequent urination, some evidence suggests that a specific chemical extracted from saw palmetto decreases night-time urination and increases the rate at which urine flows from the bladder.

Claims that it increases sperm production, breast size, or sexual vigor are unproved, as are claims that it has anti-inflammatory and anticancer properties. There is no clear evidence that saw palmetto increases hair growth in people with male pattern baldness.

Side Effects of Saw Palmetto

Headache, diarrhea, and hot flashes occasionally occur, but few serious side effects have been reported. Liver damage and pancreatitis have occurred, but it is not clear whether these were caused by saw palmetto.

Drug Interactions with Saw Palmetto

Women taking hormone therapy should consult their doctor before they take saw palmetto. Saw palmetto may interact with estrogen therapy and oral contraceptives and decrease their effectiveness. Saw palmetto

Recommendations for Saw Palmetto

Saw palmetto is generally considered safe and may decrease night-time urination and improve urine flow in men.

Because saw palmetto may have hormonal effects, children, women who are pregnant or who may become pregnant, and women who are breastfeeding should not take it.

saw palmetto or talk with their doctor before taking it.

More Information

The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.

  1. National Institutes of Health's National Center for Complementary and Integrative Health: Saw Palmetto

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