Here a post done a few month ago:
As we all know within the bodybuilding community Clenbuterol is the highly touted
beta-2 agonist with pretty impressive fat burning effects. However, there is a
downside to this incredible fat-burning
effect. Clenbuterol does its job so well binding to the beta-2 receptor(That´s involved
in both the regulation of body temperature and protein synthesis), that it
down-regulates the receptor in about 2 weeks(Assuming a dosing schedule of
60-120mcgs/day, on a 2 on/2 off day cycle). The aformentioned 2 on/2 off dosing
schedule doesn´t work because the half-life of clenbuterol Hydrochloride in the body is
48hrs, therefore it would still be present in the system during the “off” days, giving the
beta-2 receptor no time to recuperate and up-regulate.
What to do? Well, if we had a pretty benign compound that drastically increased
cyclic-adenosine monophosphate(C-amp) within the cell this would up-regulate the
elusive beta-2 receptor. You know what, it exists!, it´s called Ketotifen(brand name
Zaditen). This compund at a dosage of 6mg/ spread throughout the day will completely
negate clenbuterol´s down-regulating effects on the beta-2 receptor, due to the fact
that it increases C-amp levels within the cell by an amazing 80%.
Now, everybody is thinking: “Great, now I can take Clenbuterol forever”; however,
there is a catch.
While Ketotifen will keep the beta-2 receptor up-regulated, during the 4th or 5th week
of clenbuterol use(depending on the person), active T3 levels within the body will
decline and production of rT3 will increase(Due to the fact that Clen decreases T3
levels in the body). This will shut down Clenbuterol´s fat-burning effects. However,
there is a way one can combat this down-regulation of one´s own T3 levels. The
answer, is exogeneous T3(brand name cytomel). T3, at a dosage of 25mcgs daily will
not shut down TSH to a large degree, so therefore could be taken for quite a while(6-8
weeks). This latter dosage will boost T3 levels back to normal, helping clenbuterol
continue its fat-burning effects.
So, now we have the optimal 10 week Clenbuterol cycle:
Days 1-14: Clenbuterol at 80 mcgs daily+6mg Ketotifen daily
Days 15-70: Clenbuterol at 80mcgs daily+25mcgs T3 daily+6mg Ketotifen daily