I am only chiming in here to say that over the past 12 years, with all these crazy methods I have tried to regrow hair... the best results I have seen were when I was eating clean and working out. When I do 40/30/30 macros with no refined grains, dairy, or processed meats/foods, I feel amazing and my hair looks amazing. Working out 5x a week supercharges this effect. Come holiday season when it drops off.... shed shed shed. I seem to have a yearly hair cycle. When your body is trying to process unwanted foods and chemicals, how can it perform normal daily functions, such as grow healthy hair / nails / etc? So maybe this is how your Dad got results?