Generally a thermogenic supplement is a combination of nutrients that temporarily boost your metabolism. Until recently most thermogenics contained a substance called ephedrine (also called Ma-Yang sp?) that has been linked to complications such as heart attack, stroke and heat stroke. At least two pro athletes may have died from heat stroke while taking an ephedrine based thermogenic. I have taken the ephedrine based stuff in the past and though it seemed to work, I did not care for the side effects, it was like chugging a pot of coffee. The new stuff is ephedrine free and should be safer. After two days on the EAS Thermo Dynamx and not changing anything else I’m down a pound but I’m not going to give it my recommendation until I have been on it for a week. I can drop a pound one day and be up 2 the next so a longer period is needed for me to be somewhat confident that it is doing any good.