I buy this product because I want to do something about my arm , which in all honesty , be get a little on the flabby side . I know this product would not be good for muscle growth , but since what I want be tone , I take a shot . I have a decent amount of muscle build up from previous weight lifting program , but now I want a little more definition , and this have help . it be be almost three week and I can see a improved appearance in both my forearm and triceps . my biceps seem to be lag in the tone department , but since I have get result in less than three week , I be go to continue with the program and see if I can not closer to where I want to be .