Does Propecia Lead To Long Term Sexual Side Effects?

Hello - I have seen a lot of news recently on Finestride (propecia) and potentially irreversible long term sexual side effects (impotence, libido decrease). I am a healthy 29 year old male, taking the drug (propecia) for male pattern baldness. I have been taking it for 3 years and have not experienced any of the side effects, but I'm now very concerned with the drug. Should I discontinue usage? Is there truth to these studies?