Tweeti read on dat's forum that clen is not as anti-catabolic as once thought. sorry, i have no studies to back that up at the time. i will say that personally, i can't stand clen because of the way i feel on it: jittery, cramped, headaches. it did seem to recomp me pretty well the first time i used it, but after that i didn't notice much from it except the side effects.