I'm a nurse and serial dieter until about 2 years ago, I had tried everything - all pills teas etc u name it i tried it, I tried ephedra (bought it over the internet) and its like pill-form Speed. Not want to alarm you but it does follow in the footsteps of all diet pills from the 70's which contained a form of amphetamine. Places an enormous strain on the heart muscles and basically you don't eat as the hunger goes away yet you have plenty of energy so can still exercise or whatever
Hope that helps.