I have been on it for about 4 weeks now...the first time I used it I was doing one scoop. Nothing. So I was talking to the GNC guy (I know...its like talking to a wall) but he said try three scoops since I weigh over 200 pounds. So I tried the 3 scoops and the first week, I was trying to rip the machines from the floor. But since then its been nothing. Just energy I guess. I am going to take it back cuz the guy told me to try it out and let him know what its like. I personally don't think its worth the price IMO...