Hi, all legit finasteride contains finasteride.
I've mentioned this before, I was originally on Proscar for 7 years, then Cipla Fincar (5mg version of finpecia) for a further 7 years and was very very almost unnoticeably losing ground after 7 years on fincar.
I only noticed a difference after 14 years+ on finasteride when I swapped to another obscure generic, and my hair magically improved over the next 2 years.
So its not a question on whether all finasteride works or not (which it does) its more a question of, will everyone get exactly the same results with every brand they try when compared over a 20 year period
A lot of this also seems to have to do with how much of your hair finasteride is actually maintaining, as for me the problem has been magnified now that 100% of my front and mid scalp hair is being is artificially held in from finasteride.
for people who only have a small amount of their hair affected by finasteride, then its likely that they will have similar results to my first 14 years when I couldn't really tell any difference between brands.
