I have never used a T500, as I would too assume it would hurt, badly. I have used GP T400 though, and found it to not be anymore painful than Sust. On the other hand, I had heard of a couple guys that did feel pain. So I think it is very individual. You'll know soon enough if it's fake, based off your response, or you could always go to your Dr and get labs. I don't believe Naps has a T500, but if this is the place you got it, I'm sure its good. He wouldn't risk his long time rep off of selling a fake product