The very first time that the drug Finasteride was used was in 1992. It was administered to manage a case of benign prostate enlargement, at a dose of 5 mg. Imperato-McGinley when carrying out research in a village in the Dominican Republic, found that males who had low levels of the 5 alpha-reductase enzyme, did not suffer from hair loss and they also had smaller prostates. Thus was because they had low levels of DHT.
Thus, Finasteride was crafted to block the 5 alpha reductase enzyme and this helped decrease the size of the prostate gland as well as battled hair loss. It took 20 years for the drug to get developed, manufactured and approved for medicinal use.
In 1997, Finasteride received the FDA approval to manage male pattern hair loss at a dose of 1 mg.