Saw Palmetto extract comes from the berries of a small palm tree native to the West Indies and the Southeast coast of the United States. It is composed mainly of saturated and unsaturated fatty acids and plant sterols.
The main use of saw palmetto is in the treatment of benign prostatic hypertrophy or enlargement of the prostate gland. Benign prostatic hyperplasia is thought to be the result of testosterone accumulation in the prostate gland. Once inside the prostate, testosterone is converted chemically to another potent compound called dihydrotestosterone. This substance stimulates the cells of the prostate gland to multiply excessively. Saw palmetto appears both to inhibit the conversion of testosterone to dihydrotestosterone and to prevent dihydrotestosterone from being taken up by the cells of the prostate. With less dihydrotestosterone in the prostate cells, the rate of multiplication is slowed.
Saw palmetto may interfere with the absorption of iron.