Does saw palmetto relieve the symptoms of an enlarged prostate?

In April, 2000, the United States Pharmacopoeia (USP) reviewed the nine best-designed trials of saw palmetto and concluded that “these studies provide evidence of moderate scientific quality that commercial extracts of saw palmetto at a dose of 160 mg twice a day are more effective than a placebo in relieving lower urinary tract symptoms of benign prostatic hyperplasia including frequency, urgency, dysuria, nocturia, and impaired urinary flow. These effects are reported to begin within 30 days of treatment and to continue through at least 6 months, the longest period studied to date... Saw palmetto extracts do not significantly affect prostatic size or reduce PSA (Prostate Specific Antigen) levels in the blood; nor do they appear to alter sexual function. Common side effects are mild and not consistently different from those reported in patients on placebo. No serious adverse events are known to be associated with saw palmetto.”

For the USP announcement and a summary of their review

For a copy of their full Monograph on saw palmetto. Follow the instructions on the webpage (the copy is free).

For the Medline abstract of the large trial comparing saw palmetto with finasteride (Proscar), which concluded that “both treatments relieve the symptoms of BPH [benign prostatic hypertrophy] in about two-thirds of patients,”