I've used it with good results in the past, but don't really use it much any more. Seems like the sides are more pronounced now that I'm older, shaky, racing hearbeat and such. I don't really use it much any more. I'm sort of in the same boat as Lizard King with it being more of a risk vs. reward. I can usually get close to my goal tigtening up my diet and leaving the clen out. Although for some depending on your specific goals, it could be a benefit.