Please, do not take 50 mg of Ephedrine at once. It has a ~4 hour half life. You want to keep it in your system at all hours at least while you are awake. Dexaprine XR contains Caffeine and Yohimbine. Effectively making it the ECY stack. You need to break those tablets in half and take half a tablet every 4 hours. So you will be taking 50mg a day, but 12.5 at a time. If you really want energy add Dexaprine XR, do not kill yourself taking to much ephedrine at once.