Proscar half life is 6 hrs (if you are young and have good liver function). If you are older and your liver function is marginal the half life is longer ie 8 hrs. Having said that, the effect of finasteride may last 5-6 days after stopping it due to the duration of its blocking effect on th...
Propecia and Proscar are essentially the same drug ie Finasteride. Finasteride reduces the production of Dihydrotestosterone (DHT). Excess DHT causes miniaturization of the hair follicle, resulting in hair becoming very short and fine over time before falling out. The only difference be...