Propecia.
Propecia significantly reduces DHT (a substance in the body that can shrink the hair follicle until it no longer produces visible hair), by inhibiting the formation of DHT in your scalp
Propecia is the first and only FDA-approved pill proven to treat mild to moderate male pattern hair loss on the vertex (top of head) and the anterior mid-scalp area (middle front of head).
Taken daily, Propecia helps reduce further hair loss and regrow visible hair. Patients usually see results in three to 12 months.