Saw palmetto (Serenoa repens), used by more than 2 million men in the United States

Saw palmetto (Serenoa repens) is used by more than 2 million men in the United States for the treatment of benign prostatic hyperplasia (BPH), a non-cancerous enlargement of the prostate gland. A number of studies suggest that the herb is effective for treating symptoms, including too-frequent urination, having trouble starting or maintaining urination, and needing to urinate during the night. But a well-conducted study published in the February 9, 2006 edition of the New England Journal of Medicine found that saw palmetto was no better than placebo in relieving the signs and symptoms of BPH.