I too have noticed the same problem. I stopped taking Propecia less than a week ago after 7 years. Whilst taking propecia, I have noticed that my tolerance to alchohol has been severely reduced, and it takes me days to get over even a small amount of alcohol. I just assumed that it was the normal ageing process (I’m currently 37), but people older than me have told me that my body shouldn’t be slowing down this early. I first noticed the problem four years ago. I had tests via my GP, but they all came back fine. However I know there was something not right, and now what I have read about here on this thread all makes sense.
I’m aware that the liver is one of the few organs in the body that can repair itself. I’m hoping now I stopped taking Propecia that this will be the case.