The plant’s berries can be made into tea. Saw palmetto is also available as tablets, capsules, and a liquid extract.
Saw palmetto opposes the actions of testosterone. People take saw palmetto mostly to treat benign enlargement of the prostate gland (benign prostatic hyperplasia). In a number of studies, saw palmetto relieved the symptoms of an enlarged prostate gland, such as the frequent urge to urinate. However, a large, well-designed study did not show any benefit.
Claims that it increases sperm production, breast size, or sexual vigor are unproved.
Headache and diarrhea occasionally occur. Because saw palmetto may have hormonal effects, women who are pregnant or who may become pregnant should not take it. Women taking hormone therapy should consult their doctor before they take saw palmetto. Saw palmetto may interact with estrogen therapy and oral contraceptives and may affect the blood clot–preventing effects of warfarin.