Finasteride, the active medication in Proscar and Propecia, has been around for over 10 years. It is a medication that blocks the activation of testosterone to it’s active metabolite, dihydrotestosterone. This allows it to reduce the size of the prostate by 50% or to reduce the effects of testosterone on the hair follicle, thus leading to prostate shrinkage and potential hair growth.
We had know that a few men would have some sexual side effects from the medication, including reduced semen production, but the latest FDA update has claimed that there are valid, and rare reports of continuing sexual dysfunction that persists after the medication is stopped. This was not thought to be a valid concern, but it appears to happen in rare instances.
So, the use of this medication is still appropriate, but this side effect profile needs to be included in considerations when deciding on treatment for hair loss or prostate growth