WHoever is telling you that you need to "clean receptor sites" for this type of drug is talking fantasy. Ephedrine, Clen and theophylline were all made to be taken every day by asthma patients, so that idea is non sense. IF your "clen" is making you tired, then my guess is that it's fake. If anything, it should increase your heart rate and make your hands shake. Both of those don't synch with being tired. All I can say is be careful of your source and be 100% that what you have is 100%.