I was on Proscar for at least a year, maybe two, I don't remember, from my doctor. Then I switched to dutasteride for 6 months. I don't think I lost any hair, though I was really worried about switching to a generic and a different drug. I've been on fincar for 2 years now. From what I can tell, I have not lost any hair. When I shaved my head once, I saw my crown is thinning. It is not noticable once it is 1/2 inch long. I don't know if that is recent, or if I just never looked there before since I never shaved my head before except in the military, and did not have two mirrors back then.
I wonder if my hairloss would have just been very slow, or if the fact I did not get a huge shed after getting off proscar proves the generics are real. Well, my hair is fine, though after plenty of time to inpect at different lengths, I now know exactly where the thin spots are. Hopefully Nizoral 2% fixes them since I am too lazy for topicals.