Saw palmetto (Serenoa repens/Sabal serrulata) is a palm-like plant with berries. The berries were a staple food and medicine for the Native Americans of the southeastern United States. In the early 1900s, men used the berries to treat urinary tract problems, and even to increase sperm production and boost libido. Today, the primary use of saw palmetto is to treat benign prostatic hyperplasia (BPH), a non-cancerous enlargement of the prostate gland. Researchers aren't sure exactly how saw palmetto works. But it contains plant-based chemicals that may be effective for BPH. Researchers think that saw palmetto may affect the level of testosterone in the body, and perhaps reduce the amount of an enzyme that promotes the growth of prostate cells. Saw palmetto also seems to have an anti-inflammatory effect on the prostate. At least one study has shown even greater anti-inflammatory activity when saw palmetto is combined with lycopene and selenium.