I have been taking Xenadrine for a couple of weeks now. I workout in the mornings when I get up, on an empty stomach. I have found that if I take the Xenadrine(with or without) eating before I workout, I end up shaking so bad by the time I'm done with the Cardio part of my workout(15 min on Eliptical machine), I can't do anything else . I have started working out then taking the Xenadrine about an hour or so before I eat and I think I have balanced out . I eat a lot less and feel full and I have A LOT more energy. My 2 cents ~CB~