Is it possible that generic finasteride is not as good as the brand names Proscar and Propecia?

I have heard this from some patients that they feel that the generic drugs are not working as the original brand drugs worked. Generic finasteride drugs (Propecia or Proscar) are regulated by the FDA. Dr. Ready Pharmaceuticals, for example, is a major suppler of generic finasteride and I have check that the drugs that they produced are manufactured according to the FDAs Good Manufacturing Procedures. As a buyer, you can always use the more expensive brand name if this does not work for you. I am not equipped to tell what is the difference between two samples of finasteride. I know that there are, unfortunately, many counterfeit drugs on the market purchased through the internet without FDA overview.