As my other colleagues mentioned, taking exogenous testosterone will not affect the transplanted hairs as they are DHT resistant, however it can lead to increased miniaturization and loss of the existing hairs. For this reason it's a good idea to be on Finasteride while you take T. Good luck! Dr. Rome
Use of testosterone will not have an adverse effect on your grafts but could lead to more rapid loss of your native hair. Discuss this with your surgeon and consider starting finasteride (Propecia).