Interesting , so not to steal this thread but im curious , iv been running man powers ephedrine for about 3 weeks now and its working good , could I use clen for 2 weeks and then go back to the ephedrine or are my beta receptors way to down regulated and there would be no point in using the clen since iv been on the ephedrine for 3 weeks , and if I could use the clen would the ephedrine do anything after the 2 weeks of clen or no since the beta receptors are down from the clen and previous 3 weeks of ephedrine ??