Testosterone Replacement Therapy post Gastric Bypass

I have always had issues with low testosterone and have been on replacement meds before. The hope was some of this condition being improved with weight loss. However after my check in today my doctor has prescribed me the testosterone patch. My questions is whether other men have had to go in this direction. Any side effects you had in terms of weight gain or loss? Body definition? 

Any advice that can be provided will be greatly appreciated!