It is well understood that Clenbuterol use cause fast down-regulation of beta 2 receptors. This is due to the powerful stimulatory result of the drug. It is for that reason meaningless to utilize clen for lengthy durations without a break. Some believe that a 2 day on, two time off application schedule will certainly allow adequate possibility for receptor up-regulation. Nonetheless, I question this to be the case because of the relatively long fifty percent life of clen, resulting in continued stimulation also throughout the ‘off’ days. A far better regimen would be a two week on, 2 week off pattern. Maximum plasma degrees are reached around 2-3 hrs after dental management, and also terminal fifty percent life at 34 hrs (Zimmer, 1976).