Herbal Extract For Battling Baldness

Q. Several months ago I started taking 160 mg/day of saw palmetto extract to slow the progression of male pattern baldness. To my surprise, the regimen seems to work. There is less hair in the bathroom sink and I have noticed new growth on the temples.
I haven’t experienced any noticeable side effects such as loss of libido. I looked in the medical literature for long-term side effects but found none. The longest clinical trial (for prostate enlargement) lasted two years. Do you know of any health hazards with saw palmetto extract?
A. Mild digestive tract upset is the most common complaint with saw palmetto extract, and even that is rather infrequent. Impotence is also rare, reported by about one percent of men (JAMA, Nov. 11, 1998).
Saw palmetto is thought to block the same enzyme as finasteride (Propecia). This prescription drug has been approved for treating male pattern baldness. One small study (J. Altern. Complement. Med. Apr. 2002) showed the herb was more effective than placebo in stimulating hair growth.