I've heard it all...Run both at the same time...Don't run both...run them by switching them every 2 weeks...Using Zedatin and or Benedryl...I've had success with running them separate, switching every couple of weeks...eca will not cause such a pronounced down regulation and desensitization of the receptors, at least not like clen does. Ephedrine has a short half life compared to clen. With ephedrine, there are times throughout the day where the betas will partially recover from stimulation by adrenaline and nor-adrenaline.