Ephedrine scares me because I have sinus tachycardia (an overly fast heart rate). I have to be careful even with caffeinated drinks. I allow myself no more than 2 6oz (177ml) cups of coffee a day or I get the shakes & palpitations. I do drink inordinate amounts of tea though. I'm talking upwards of 1-1.5 gallons (3.8-5.7 liters) of tea every day. There is probably quite a bit of caffeine in that but it doesn't seem to bother me like coffee or caffeine pills do.