Dihydrotestosterone (DHT) is a biologically active metabolite of testosterone. It is formed primarily in the prostate gland, testes, hair follicles, and adrenal glands. Scientific research has discovered that DHT is the primary contributing factor in male-pattern baldness. DHT also plays a role in the development or exacerbation of benign prostatic hyperplasia (BPH) and prostate cancer.

Recent medical research in the area of prostate health has involved the development of drugs and supplements, which will block or at least inhibit the production of DHT. There are a number of drugs on the market that act as DHT blockers, including finasteride (sold under the names Proscar for BPH and Propecia for androgenic alopecia) and dutasteride (sold under the name Avodart). There is also a natural DHT blocker, Saw Palmetto, which has shown promise in the treatment of BHP and hair loss.

Saw Palmetto is an extract of the fruit of Serenoa repens. It is grown in the Southern region of the United States and was first reportedly used for medicinal purposes by Native Americans. For years homeopathic physicians have been prescribing Saw Palmetto extract for male patients experiencing prostate enlargement, and there is a well documented history of it providing relief for patients afflicted with BHP.

An interesting side effect of Saw Palmetto has also been noted. Some male patients report that they have experienced noticeable and permanent regrowth of scalp hair or a solid reduction in the rate of hair loss while taking Saw Palmetto for prostate problems. This has led to recent research, which seems to conclude that inhibiting or blocking DHT production affects the entire body not just the prostate. It is believed that Saw Palmetto may block the enzyme (5-alpha-reductase) from converting the hormone testosterone into DHT. In the scalp area, the reduction of DHT seems to allow hair follicles to re-open and engage in new hair growth. Evidence also shows that DHT reduction may also maintain the health of productive follicles.

For men suffering from male pattern baldness it appears the Saw Palmetto's natural DHT blocking ability may lead to a stoppage of hair loss and in some cases hair regrowth. Saw Palmetto is widely available in both crushed berry and extract form and is a major ingredient in natural hair loss treatments such as Provillus and Procerin. For use as a DHT blocker the recommended dosage of Saw is 300-600 milligrams daily mixed.