An ex-Marine I know was on the treadmill in Power House gym, he had a heart attack-21 years old. He was taking the original Hydroxycut with ephedra. He lived, but told everyone his doctors suspected it was linked to the supplement as he had no existing heart condition.
I've provided a paragraph from a popular medical site I often refer to, I've also included the link for your enjoyment. Unless of course, you are armed with more Knowledge then the FDA and the medical industry, in which case, my apologies in advance.
"Unfortunately, clinical trials, research and several studies have shown that there have been many hazardous side effects associated with the use of fat burners. Therefore, you must be careful about which fat burner supplement you choose for yourself. For example, just for ephedrine, the FDA (Food & Drug Administration) has registered hundreds of reports of frequent side effects occurring in its regular users. Clinically documented adverse reactions include high blood pressure, muscle twitching, lack of sleep, dry mouth, cardiac palpitations, irritability, paralysis, and even death in some acute cases.
Also, according to a study conducted by FDA, frequent use of ephedrine could even lead to permanent disability. It is, therefore, not considered as safe fat burning supplement. There are also some Chinese herbal supplements available in the market that can give you similar results but are considered as equally hazardous."
http://blog.proactol.com/2010/diet-p...f-fat-burners/