Common Names: saw palmetto, American dwarf palm tree, cabbage palm
Latin Names: Serenoa repens, Serenoa serrulata, Sabal serrulata
- Saw palmetto is a shrublike palm native to the southeastern United States. Historically, it was used for a variety of conditions, including disorders of the male and female reproductive organs and coughs due to various diseases.
- Currently, saw palmetto is promoted as a dietary supplement for urinary symptoms associated with an enlarged prostate gland (also called benign prostatic hyperplasia or BPH), as well as for chronic pelvic pain, migraine, hair loss, and other conditions.
How Much Do We Know?
- Many studies have evaluated various preparations of saw palmetto for urinary tract symptoms associated with prostate enlargement in men.
- Much less is known about the use of saw palmetto for other health purposes.
What Have We Learned?
- Two large, high-quality studies funded by the National Institutes of Health (NIH), each using a different preparation of saw palmetto, found it was no more effective than a placebo (an inactive substance) for BPH symptoms. Saw palmetto products are made in a variety of ways and differ in composition. Some studies of saw palmetto products other than those used in the NIH-sponsored studies have suggested that they might be helpful for BPH symptoms, but many of these studies were of low quality. No saw palmetto product has been conclusively shown to be effective for BPH.
- There isn’t enough research on saw palmetto for conditions other than BPH to allow any conclusions to be reached.
What Do We Know About Safety?
- Saw palmetto is well tolerated by most users. It may cause mild side effects, including digestive symptoms or headache.
- Saw palmetto does not appear to affect readings of prostate-specific antigen (PSA) levels, even when taken in higher-than-usual amounts. PSA is a protein produced by the prostate gland. PSA levels have been used to screen for prostate cancer and are also used to monitor patients who have been diagnosed with prostate cancer.
- Saw palmetto has not been shown to interact with medications.
- Information on the safety of saw palmetto comes primarily from studies of its use for BPH in men. Little is known about the safety or side effects of saw palmetto when used for other conditions, especially in women or children.
- Saw palmetto may be unsafe for use during pregnancy or while breastfeeding.
Keep in Mind
- Urinary tract symptoms can have several causes, including conditions such as prostate cancer that need prompt treatment. If you’re having problems with urination, it’s important to tell your health care provider.
- Take charge of your health—talk with your health care providers about any complementary health approaches you use. Together, you can make shared, well-informed decisions.
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- Agbabiaka TB, Pittler MH, Wider B, et al. Serenoa repens (saw palmetto): a systematic review of adverse events. Drug Safety. 2009;32(8):637-647.
- Andriole GL, McCullum-Hill C, Sandhu GS, et al. The effect of increasing doses of saw palmetto fruit extract on serum prostate specific antigen: analysis of the CAMUS randomized trial. Journal of Urology. 2013;189(2):486-492.
- Avins AL, Lee JY, Meyers CM, et al. Safety and toxicity of saw palmetto in the CAMUS trial. Journal of Urology. 2013;189(4):1415-1420.
- 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, Chan M. Saw palmetto. In: Coates PM, Betz JM, Blackman MR, et al., eds. Encyclopedia of Dietary Supplements. 2nd ed. New York, NY: Informa Healthcare; 2010:700-710.
- De Monte C, Carradori S, Granese A, et al. Modern extraction techniques and their impact on the pharmacological profile of Serenoa repens extracts for the treatment of lower urinary tract symptoms. BMC Urology. 2014;14:63.
- Miroddi M, Carnì A, Mannucci C, et al. Hot flashes in a young girl: a wake-up call concerning Serenoa repens use in children. Pediatrics. 2012;130(5):e1374-e1376.
- Novara G, Giannarini G, Alcaraz A, et al. Efficacy and safety of hexanic lipidosterolic extract of Serenoa repens (Permixon) in the treatment of lower urinary tract symptoms due to benign prostatic hyperplasia: systematic review and meta-analysis of randomized controlled trials. European Urology Focus. 2016;2(5):553-561.
- Saw palmetto. Natural Medicines website. Accessed at naturalmedicines.therapeuticresearch.com on December 19, 2019. [Database subscription].
- Tacklind J, MacDonald R, Rutks I, et al. Serenoa repens for benign prostatic hyperplasia. Cochrane Database of Systematic Reviews. 2012;(12):CD001423. Accessed at https://www.cochranelibrary.com/ on December 19, 2019.
- Ye Z, Huang J, Zhou L, et al. Efficacy and safety of Serenoa repens extract among patients with benign prostatic hyperplasia in China: a multicenter, randomized, double-blind, placebo-controlled trial. Urology. 2019;129:172-179.
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