Most of the time I use it for testosterone replacement therapy because I have the medical condition of low testosterone and I refuse to let my insurance dictate how my treatment is going to work. It’s literally the same exact thing they use at the doctors office. It works unbelievably well. And once or twice a year I go up on my dose to gain muscle size and I easily go from 250 pounds to 270 pounds. My testosterone was off the charts the one time I asked my doctor to test me. So no matter what you use this for, gaining huge amounts of muscle or for testosterone replacement it works perfectly! And let’s not forget how awesome the customer service is here. Absolutely the best!