ECA screws with me bigtime. When I was in highschool I worked a job where I got off at 1-2am. every night of the week. I popped caffine pills like crazy to stay awake in class. I would even crush the stuff up and snort it when I had to (Don't do this). Back then it didn't effect me at all. White crosses(ephedrine) black molle, 20/20 and 357s all the time. Now it seems as though I have become intolerant of the stuff. I can take half a metabolife 356 and drink a couple a cups of coffee and my heart goes crazy. Skipping, pounding, palpitations, nervous sweats you name it, I can't take the stuff.