What is Finasteride/Propecia (part one)?

Finasteride was originally developed to relieve symptoms associated with benign prostatic hyperplasia (BPH), an enlargement of the prostate gland common in men over 50. While testing a 5 mg dose of the drug for those purposes in the early 1990s, unforeseen benefits for the retention and stimulation of hair growth on the head were observed. The 5 mg dose went on to be approved for prostate treatment by the US Food and Drug Administration (FDA) and marketed by pharmaceuticals giant Merck as Proscar. Further trials led to a 1 mg dose for hair loss entering the market branded as Propecia, when on 22 December 1997 Finasteride was approved by the FDA as the first clinically proven systemic treatment for male pattern baldness. Finally men hoping to slow, stop or even reverse the process of balding had a successful pharmaceutical treatment at their disposal.

Available only with a doctor's prescription, Finasteride counters hair loss by chemically preventing the metabolism of testosterone into dihydrotestosterone (DHT) within the body. It achieves this by targeting and inhibiting type II 5-alpha-reductase, one of two types of an enzyme able to facilitate such a conversion. By interfering with this process Finasteride greatly reduces the amount of DHT present in, among other tissue in the body, the scalp. The detrimental effect that DHT has on the vitality of the individual follicles and hairs of susceptible individuals can thus be negated, or more accurately, deferred.

More tomorrow...