Saw palmetto has a long history of being useful in the treatment of benign enlargement of the prostate gland (BPH), a condition that affects many men over the age of fifty. The cause of BPH is still not completely understood, but a likely factor is thought to be the conversion of the male hormone, testosterone, to a derivative known as dihydrotestosterone (DHT) via the enzyme 5-alpha reductase. Laboratory studies show that saw palmetto is able to inhibit the action of this particular enzyme, which may account for its success in treating BPH.
One of the causes of male pattern baldness (alopecia) is excess DHT in hair tissue. It seems reasonable to assume that, because saw palmetto is able to reduce the buildup of DHT in the prostate, it may also do the same in hair tissue and, therefore, be beneficial in counteracting baldness. Incidentally, this is the same mechanism by which the hair-loss drug, Propecia, works.
As yet there is very little research into the use of saw palmetto as a baldness cure, but the only study thus far reported, conducted by Prager et al (J Altern Complement Med 2002; 8(2): 143-152), showed a positive response to treatment. The double-blind trial reported that 60% of subjects who were dosed with saw palmetto were rated as improved, compared with only 11% of the placebo group.
More research is needed to verify the above result and also to quantify aspects like dosage levels and long-term benefits. At this stage, however, it looks like saw palmetto may be a natural, side effect-free alternative to the currently available drugs that are used to counteract male pattern baldness.