I had taken a decongestant while in the U.S. not realizing that Ephedrine is a common ingredient, and I and it was terrifying! How can people choose to take something that causes your heart to fluctuate and flutter like that?!
That aside, I do know that many people react differently to the same drug. I've never needed to enlist in a dietary aid to lose weight, but from friends experiences, Hydroxycut is strong stuff, can keep you up at night and cause heart palpitations. I also have to add from knowing and watching these people, I haven't found that the meds made any difference that a healthy diet and moderate exercise wouldn't have done alone.