Clenbuterol is a beta 2 agonist which has a limited anabolic effect during its first few days of use and afterward is normally used to fight fat. At higher doses, however, it can be catabolic to muscle and it must be cycled on a 2 week on, 2 week of basis or the beta 2 receptors that clen binds to become saturated and down regulate.
Ketotifen’s magic is that it upregulates the beta-receptors including the beta 2s that clen uses. As long as you are taking ketotifen, it will continue to clean these receptors, never allowing them to downregulate – even while on a heavy clen cycle. That means you can continue to take clen indefinitely without having to cycle off to regenerate the receptors. 2-3mg ED can upregulate even severely shut down receptors within a week.
It also means that you don’t need as much clen to get the same benefits. It seems u can take about 30-40% less clen and it be equally effective. It has also been thought that it also increases the number of receptor sites on the surface of the cell, allowing more clen to attach and perhaps this is the reason for the increased efficacy. Ketotifen also seems to lessen the sides of clen including the jitters.
Please Scroll Down to See Forums Below 
