Saw palmetto, a common palm tree found in the southeastern United States, is best known as the source of a popular treatment for prostate problems. The active ingredient comes from an extract of the tree's berries.
Uses: Available as dried berries, teas, tinctures, fluids, gelatin capsules and tablets, saw palmetto is taken by some men to treat benign prostatic hyperplasia, a condition that affects many men after age 30. The risk increases with age. Men with the condition may have increased nighttime urination and trouble urinating.
Dose: The typical dose is 325 milligrams daily. Products that are considered of high quality are those with labels stating that the dose contains 85% to 95% fatty acids and sterols, which is the formula typically used in studies on the herb.
Precautions: Although benign prostate hyperplasia can be diagnosed only by a doctor, saw palmetto supplements appear safe and nontoxic. Taking the supplement does not affect levels of serum prostate-specific antigen, or PSA, which is measured during screening for prostate cancer.
Research: The federal government is conducting a large, randomized clinical trial to test the effects of saw palmetto for relieving benign prostatic hyperplasia symptoms. Several smaller studies have suggested saw palmetto helps, but those studies generally were of poor quality.
Dietary supplement makers are not required by the U.S. government to demonstrate that their products are safe or effective. Ask your health-care provider for advice on selecting a brand.