Saw Palmetto

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Saw Palmetto

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What is saw palmetto?

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. 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 Canada, saw palmetto is available as a dietary supplement.

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.

What is saw palmetto used for?

People use saw palmetto to treat the symptoms of an enlarged prostate (BPH).

Studies conflict on whether saw palmetto improves men's symptoms. In one study, men taking saw palmetto were no better than those who took a placebo.2

But two reviews of trials on different saw palmetto preparations report that more men rated their symptoms improved while using saw palmetto compared with a placebo. The reviews also report that:1

  • The medicine finasteride was slightly more effective at improving symptoms than saw palmetto.
  • The risk of erection problems when using saw palmetto was less than when using finasteride.

Saw palmetto improves a man's ability to urinate by allowing urine to flow out of the bladder faster and reducing the number of times he needs to get up during the night to urinate.

Is saw palmetto safe?

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 Natural Health Products Directorate (NHPD), within the Health Products and Food Branch of Health Canada, regulates dietary supplements in Canada. Dietary supplements, including saw palmetto, must be reviewed and approved by the NHPD before they can be sold in Canada.

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 non-prescription 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.

References

Citations

  1. Webber R (2006). Benign prostatic hyperplasia, search date May 2005. Online version of BMJ Clinical Evidence. Also available online: http://www.clinicalevidence.com.
  2. Bent S, et al. (2006). Saw palmetto for benign prostatic hyperplasia. New England Journal of Medicine, 354(6): 557–566.

Other Works Consulted

  • Murray MT, Pizzorno JE (2006). Serenoa repens (saw palmetto). In JE Pizzorno Jr, MT Murray, eds., Textbook of Natural Medicine, 3rd ed., vol.1, pp. 1245–1250. St. Louis: Churchill Livingstone Elsevier.
  • Saw palmetto (2009). In A DerMarderosian et al., eds., Review of Natural Products. St. Louis: Wolters Kluwer Health.

Credits

By Healthwise Staff
Primary Medical Reviewer Kathleen Romito, MD - Family Medicine
Primary Medical Reviewer Donald Sproule, MD, CM, CCFP, FCFP - Family Medicine
Specialist Medical Reviewer Marc S. Micozzi, MD, PhD - Complementary and Alternative Medicine
Last Revised October 12, 2009

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