Researchers have discovered that men who suffer from male pattern hair loss have increased levels of dihydrotestosterone (DHT). DHT is produced from testosterone by an enzyme called 5-alpha-reductase. Biochemical analysis reveals higher levels of 5-alpha-reductase in the scalp of balding men, and less of it in men with no hair loss. Propecia inhibits 5-alpha-reductase, blocking the formation of DHT. This interrupts a key element in the development of male pattern hair loss.

Regaine Extra Strength is another threatment that may help, it contains minonidil 50mg/ml and is for topical use on the scalp only