the t3 will increase your metabolism allowing for better protein synthesis and more calories burned. it is very catabolic to muscle tissue, depending on what your cycle is it may not be to bad. i think biggerisbetter is confused on his above post, the dnp is actually quite muscle sparing. it will not technically increase your metabolism but you will burn a significant amount of fat. i would go with DNP, but please do your research on the substance before you try it. it is not a drug for those uneducated in its dangers. also, DNP has had a bad aura around it due to the crackdown by the FDA, so be careful who you buy from