Finasteride usually start quickly by reducing shedding and then stopping or slowing the hair loss in a few months. Reversal, if it is to occur, will happen between 4-18 months. Some men don’t ever see new growth and have to accept slowing the loss of stopping the hair loss. A few men will find increased shedding when they start taking finasteride. This is a sign that it is working so i tell these men not to worry, just be patient.