clenbutrol for longer than 2 weeks?

i would like to see your view points on the use of clenbutrol for more than 2weeks,apparently it can be used for 12weeks and still exhibit a fat burning effect www.rxmuscle.com/articles/chemical-enhan...-and-fat-burner.html i dont quite know if i buy it though....

Whenever I've used clenbuterol, I see a major differnce in the first week. By the end of the second week it has all but stopped working. By third or fourth it's a waste-not even getting the shakes anymore.

I've tried it with Betasleep for the Diphenhydramine Hydrochloride, which is supposed to upregulate the beta receptors on 50mg per day. There was a bit of an improvement on the staying power, but still after 4 weeks feels like it's doing nothing.