Androgenic alopecia. For my case.

I've done my hairs transplanted on 02.05.16 (3000 grafts fue). I've never used finasteride and minoxidil after that. But now (01.06.17) my transplanted hairs are getting thin. I've discussed with my doctor, he suggested me to take biotin tablets and saw palmetto local application. I am taking biotin tablets and applying saw palmetto gel regularly from past 3 more months but the hair quality is not improving and I'm losing 10-15 hairs daily while washing. Shall I have to apply minoxidil to retain my transplanted hairs. (I've applied minoxidil 5% and 10% along with finasteride 1mg in the year 2015 i.e. before hair transplant But when I discontinued it I've lost many hairs after that.) Also tell me about dermaroller treatment for my case.