way before my hairtransplant procedure, I spoke with my personal doctor about hair loss. He started me on finasteride. He was probably a norwood 6 and was taking finasteride for his prostate I believe. The hair that grew back on his crown was nothing less than impressive just from the finasteride he states. He wasn't even concerned about his hair loss, it just started growing and was impressed because he wasn't even trying to fix his hair loss problem.
I also spoke with a reputable doctor on this forum and told him what my personal doctor stated that it grew hair back on his crown, and he said he had never heard of that. He said it just maintains your current hair. He didn't believe me in other words.