WOW! Thats all I have to say. I drank half of one once. That was more then enough for me. I can't deal with it. I am not sure what its in it, but it doenst like my body. I get very little caffeine or anything like that in my diet though. I have a few friends, body builder types, that love the stuff when they lift. I can't handle it. If I were to train with something like that, I think my heart rate would go through the roof!