PROPECIA [Finasteride], one of the newest medications for the treatment of androgenic alopecia and is a product of Merck & Co. Before commenting on the drug, a few lines on what is androgenic alopecia. Androgenic alopecia is a hereditary disorder due to excessive conversion of testosterone to dihydrotestosterone in the scalp skin in genetically susceptible men and women. The dihydrotestosterone causes shrinking of the local terminal hair follicles to miniaturized hair follicles. 
The plasma levels of testosterone are appropriate for the sex. The onset of androgenic alopecia in both the sexes is early in life, often in teens. The miniaturized hair of various lengths and diameters are the hallmark of this condition. PROPECIA [Finasteride] is a 5-alpha reductase inhibitor. 5-alpha reductase is an enzyme that converts testosterone to dihydrotestosterone. The recognition potential value of PROPECIA [Finasteride] in the treatment of androgenic alopecia was based upon the observation that men congenitally deficient in 5-alpha reductase had low levels of dihydrotestosterone and did not develop male pattern baldness or prostate enlargement. 
In contrast, balding areas of the scalp have increased levels of dihydrotestosterone and smaller hair follicles than do non-balding areas 

 Type 1: This is found in the sebaceous glands [These glands secrete a substance called sebum]       

  Type 2: This is found in the hair follicles. PROPECIA [Finasteride] is a type 2 class of 5-alpha reductase inhibitor and it suppresses both, the serum and the tissue levels of dihydrotestosterone. 

PROPECIA [Finasteride] – 1 mg per day, has been shown to increase hair growth in up to 80% of men when given over a 2 year period. This drug is taken orally, 1mg per day. PROPECIA [Finasteride] increases the hair counts in both the vertex of the scalp and the frontal area of the scalp. The response to PROPECIA [Finasteride] is better in the frontal region of the scalp, which has a higher level of 5-alpha reductase than in the occipital region which has higher levels of aromatase. Increased hair growth can be observed as early as 3 months into treatment. PROPECIA [Finasteride] is approved for use only in men.
 It is not sure if it is of any benefit to women, though doctors say that it can be tried in postmenopausal women. On December 22, 1997, the FDA approved PROPECIA [Finasteride] to treat male pattern hair loss. It is a FDA pregnancy category X drug. This means that PROPECIA [Finasteride] is known to cause birth defects in an unborn baby. 
 Pregnant women should not touch broken tablets because of the potential for genital abnormalities in male fetuses, since it is widely believed that some absorption can take place through skin. No birth defects have been seen in female fetuses It is not known whether PROPECIA [Finasteride] passes into breast milk, and thus should not be taken during the lactation period. Male partners on PROPECIA [Finasteride] should use a protective device like condom while having intercourse since it may pass through semen, though Merck says that it is not an issue of concern.