heres my take : t3 results in an indiscriminate increase in metabolism...your body will get energy wherever it can ...including muscle tissue. Im not so sure about the preferring muscle to bodyfat ..i just think it increases metabolism to the point that fat oxidation alone cant meet energy needs so muscle is used. Clen ...as u prob know stimualtes fat cells while providing the increase in bmr ...thus the effectivness at burning fat while sparing muscle. Im not sure about the clen then t3 idea...your thyroid will take a beating this way downregulated from clen ...then shut down with t3 ...and so on. I have no 1st hand experince doing this so i cant comment with 100% conviction....