Bridging. When you bridge the problem is you never come off steroids. You run a 12 week cycle and then for the next 6 to 8 weeks you are running a oral steroid or a low dose of Testosterone. Where does your body have to work on its own, this long on steroids and your body now forgets how to produce its own Testosterone, the side effects never get to reside. We all no oral steroids can cause liver problems, if tylenol can send a person to the hospital for liver damage then so can these steroids. When you use them in a cycle, you can just run them, get off and your body repairs, but when you bridge your body does not get that chance.
It is well known that Clenbuterol use results in rapid down-regulation of beta 2 receptors. This is due to the powerful stimulatory effect of the drug. It is therefore pointless to use clen for long periods without a break. Some believe that a two day on, two day off dosing schedule will allow adequate potential for receptor up-regulation. However, I doubt this to be the case due to the relatively long half life of clen, resulting in continued stimulation even throughout the ‘off’ days. A much better regime would be a two week on, two week off cycle. Maximum plasma levels are reached around 2-3 hours after oral administration, and terminal half life at 34 hours (Zimmer, 1976).