Finasteride (also known as Propecia) is a hair loss treatment for male pattern baldness that is taken as a pill. It is a good option for men suffering from genetic hair loss (also known as male pattern baldness) and works by reducing the conversion of testosterone to dihydrotestosterone (DHT). It is the DHT that contributes to hair loss by causing the hair follicles to steadily miniaturize and eventually die off. This medication is effective for hair stabilization within months of taking it and hair regrowth may occur by 6-9 months, but not in everyone. The effects of finasteride are lost when you stop it.