Saw Palmetto

© Steven Foster

This fact sheet provides basic information about saw palmetto—

common names, what the science says, potential side effects and 

cautions, and resources for more information.

Common Names—saw palmetto, American dwarf palm tree, 

cabbage palm

Latin Names—Serenoa repens, Sabal serrulata

Saw palmetto is a small palm tree native to the eastern United States. 

Its fruit was used medicinally by the Seminole Tribe of Florida. Saw 

palmetto is used as a traditional or folk remedy for urinary symptoms 

associated with an enlarged prostate gland (also called benign prostatic 

hyperplasia, or BPH), as well as for chronic pelvic pain, bladder 

disorders, decreased sex drive, hair loss, hormone imbalances, and 

prostate cancer.

The ripe fruit of saw palmetto is used in several forms, including 

ground and dried fruit or whole berries. It is available as liquid extracts, 

tablets, capsules, and as an infusion or a tea.

What the Science Says

• Several small studies suggest that saw palmetto may be effective for 

treating BPH symptoms. However, a 2011 NCCAM-cofunded study in 

369 older men demonstrated that saw palmetto extract administered 

at up to three times the standard daily dose (320 mg) did not reduce 

the urinary symptoms associated with BPH more than placebo. In 

addition, a 2009 review of the research concluded that saw palmetto 

has not been shown to be more effective than placebo for this use.

• In 2006, an NIH-funded study of 225 men with moderate-to-severe 

BPH found no improvement with 320 mg of saw palmetto daily for 

1 year versus placebo.

• There is not enough scientific evidence to support the use of saw 

palmetto for reducing the size of an enlarged prostate or for any 

other conditions.
• Saw palmetto does not appear to affect readings of prostate-specific antigen (PSA) levels. PSA is a 

protein produced by cells in the prostate. The PSA test is used to screen for prostate cancer and to 

monitor patients who have had prostate cancer.

• An NCCAM-funded study is looking at the effects of saw palmetto extract on prostate cancer cells.

Side Effects and Cautions 

• Saw palmetto appears to be well tolerated by most users. It may cause mild side effects, including 

stomach discomfort.

• Tell all your health care providers about any complementary health practices you use. Give them a 

full picture of what you do to manage your health. This will help ensure coordinated and safe care. 

For tips about talking with your health care providers about complementary and alternative 

medicine, see NCCAM’s Time to Talk campaign at nccam.nih.gov/timetotalk/. 

Sources

Barry MJ, Meleth S, Lee JY, et al. Effect of increasing doses of saw palmetto extract on lower urinary tract symptoms: a 

randomized trial. JAMA. 2011;306(12):1344-1351.

Bent S, Kane C, Shinohara K, et al. Saw palmetto for benign prostatic hyperplasia. New England Journal of Medicine. 

2006;354(6):557-566.

Croom EM Jr. Saw palmetto (Serenoa repens). In: Coates P, Blackman M, Cragg G, et al., eds. Encyclopedia of Dietary Supplements. 

New York, NY: Marcel Dekker; 2005;635-644.

National Cancer Institute. The Prostate-Specific Antigen (PSA) Test. National Cancer Institute Web site. Accessed at 

www.cancer.gov/cancertopics/factsheet/Detection/PSA on June 3, 2010.

Saw palmetto. Natural Medicines Comprehensive Database Web site. Accessed at www.naturaldatabase.com on August 7, 2009.

Saw palmetto (Serenoa repens [Bartran] Small). Natural Standard Database Web site. Accessed at www.naturalstandard.com on 

August 4, 2009.

Saw palmetto berry. In: Blumenthal M, Goldberg A, Brinckman J, eds. Herbal Medicine: Expanded Commission E Monographs. 

Newton, MA: Lippincott Williams & Wilkins; 2000:335-340.

Tacklind J, MacDonald R, Rutks I, et al. Serenoa repens for benign prostatic hyperplasia. Cochrane Database of Systematic Reviews. 

2009;(2):CD001423.

For More Information

Visit the NCCAM Web site at nccam.nih.gov and view Using Dietary Supplements Wisely

(nccam.nih.gov/health/supplements/wiseuse.htm).

NCCAM Clearinghouse

Toll-free in the U.S.: 1-888-644-6226

TTY (for deaf and hard-of-hearing callers): 1-866-464-3615

E-mail: info@nccam.nih.gov

PubMed®

Web site: www.ncbi.nlm.nih.gov/sites/entrez

NIH Office of Dietary Supplements

Web site: www.ods.od.nih.gov

NIH National Library of Medicine’s MedlinePlus

Saw Palmetto Listing: www.nlm.nih.gov/medlineplus/druginfo/natural/971.html

This publication is not copyrighted and is in the public domain. Duplication is encouraged.

NCCAM has provided this material for your information. It is not intended to substitute for the medical expertise and advice of 

your primary health care provider. We encourage you to discuss any decisions about treatment or care with your health care 

provider. The mention of any product, service, or therapy is not an endorsement by NCCAM.

National Institutes of Health

♦♦♦

U.S. Department of Health and Human Services

D275

Created May 2006 

Updated April 2012