i didn't really take anything other than the otc vitamins i listed a few replies ago.
i may have had a little where my receded hairline started, but that was it.
result wise, you just need to be careful and follow the directions the Dr. gives after surgery, but the results are mostly dictated by the quality of surgeon and the amount of grafts you receive. I could have gotten as low as 2,000 grafts but got almost 2,800, the results of 2,000 grafts would have been a lot different than 2,800. So again, the more hair you put, the better results will be.