Saw palmetto is a type of palm tree that grows in the southeastern United States.
The berry of the saw palmetto plant contains a compound that may reduce the symptoms of benign prostatic hyperplasia (BPH), which is a noncancerous enlargement of the prostate gland. Symptoms of an enlarged prostate include dribbling after urination and getting up many times during the night to urinate.
From the 1870s until 1950, saw palmetto was a common treatment for prostate and other urinary problems. After 1950, saw palmetto was no longer recognized as a drug in the United States. It is still used in Europe as a treatment for BPH and is approved by the German Commission E. The Commission E evaluates herbal treatments for their safety and efficacy (how well they work).
In the United States, saw palmetto is available as a dietary supplement.
Why It Is Used
People use saw palmetto to treat the symptoms of an enlarged prostate (BPH).
Experts disagree on whether saw palmetto improves men's symptoms of BPH. Experts also don't clearly understand how saw palmetto may improve symptoms of BPH. It might stop the growth of the prostate or even make it smaller. This is how finasteride, a medicine commonly prescribed to treat BPH symptoms, works.
A review of studies done on saw palmetto showed that men who took saw palmetto had some improvement in nighttime urination. But when only the best studies were included in the review, men who took saw palmetto had no difference in symptoms, urine flow, or nighttime urination compared with men who took a placebo.footnote 2
In another study, men who took even higher doses of saw palmetto had no difference in BPH symptoms, urine flow, or nighttime urination compared with men who took a placebo.footnote 3
Few problems have been reported among men taking saw palmetto. But some men may experience stomach problems. Saw palmetto is less likely than finasteride to cause difficulty in getting an erection.
Men who have problems urinating should see a doctor to rule out prostate cancer. Prostate cancer is treatable, but treatment is most successful when you find and treat the cancer as early as possible.
If you intend to use saw palmetto to treat symptoms of BPH, look for a product that has a fat-soluble extract of the saw palmetto berry. The active compound does not dissolve well in water. So drinking a tea or water extract made from saw palmetto berries is not likely to have an effect on the symptoms of BPH.
The U.S. Food and Drug Administration (FDA) does not regulate dietary supplements in the same way it regulates medicines. A dietary supplement can be sold with limited or no research on how well it works.
Always tell your doctor if you are using a dietary supplement or if you are thinking about combining a dietary supplement with your conventional medical treatment. It may not be safe to forgo your conventional medical treatment and rely only on a dietary supplement.
When using dietary supplements, keep in mind the following:
- Like conventional medicines, dietary supplements may cause side effects, trigger allergic reactions, or interact with prescription and nonprescription medicines or other supplements you might be taking. A side effect or interaction with another medicine or supplement may make other health conditions worse.
- Dietary supplements may not be standardized in their manufacturing. This means that how well they work or any side effects they cause may differ among brands or even within different lots of the same brand. The form you buy in health food or grocery stores may not be the same as the form used in research.
- The long-term effects of most dietary supplements, other than vitamins and minerals, are not known. Many dietary supplements are not used long-term.
- Bent S, et al. (2006). Saw palmetto for benign prostatic hyperplasia. New England Journal of Medicine, 354(6): 557–566.
- Tacklind J, et al. (2009). Serenoa repens for benign prostatic hyperplasia. Cochrane Database of Systematic Reviews (2).
- Barry MJ, et al. (2011). Effect of increasing doses of saw palmetto extract on lower urinary tract symptoms. JAMA, 306(12): 1344–1351.
Current as of: March 17, 2021