There was a theory that Propecia actually gave you muscle mass due to the slight increase in testosterone.
So, my question to those who use Propecia and workout, did you notice any changes? Change in strength? Muscle?
Yes, finasteride increases total testosterone levels by 10-15%. But it also lowers free testosterone by ca. 25%. This can naturally offset the anabolic effect of the higher total testosterone.
I believe that DHT-inhibitors lower your capacity to build muscle, although only slightly. In the above mentioned study, there was no statistal difference between men taking and not taking dutasteride, but it is apparent from the graphs that men taking dutasteride consistently had somewhat worse results.