Receding hairline...

Baldness is inevitable as we grow older. The most common form of baldness is a progressive hair thinning condition called androgenic alopecia or 'male pattern baldness' that occurs in adult male humans and other species. The amount and patterns of baldness can vary greatly; it ranges from male and female pattern alopecia (androgenic alopecia, also called androgenetic alopecia or alopecia androgenetica), alopecia areata, which involves the loss of some of the hair from the head, and alopecia totalis, which involves the loss of all head hair, to the most extreme form, alopecia universalis, which involves the loss of all hair from the head and the body.

Treatments for the various forms alopecia have limited success. Some hair loss sufferers make use of so-called "clinically proven treatments" such as finasteride and topically applied minoxidil (in solution) in an attempt to prevent further loss and regrow hair. As a general rule, it is easier to maintain remaining hair than it is to regrow; however, the treatments mentioned will help some of the users suffering from Androgenetic alopecia, and there are new technologies in cosmetic transplant surgery and hair replacement systems that can be completely undetectable. The effectiveness of finasteride and minoxidil is not universally accepted.

In the USA, there are only two drug-based treatments that have been approved by the FDA (Food and Drug Administration) and one product that has been cleared by the FDA for the treatment of androgenetic alopecia, otherwise known as male or female pattern hair loss. The two FDA approved treatments are finasteride (marketed for hair loss as Propecia) and minoxidil.

Men with androgenic alopecia typically have lower levels of total testosterone, higher levels of unbound/free testosterone, and higher levels of total free androgens including DHT.

Source: Wikipedia