Road2HardCoreIron

Well... that is really a dumb question, because T4 doesn't burn anything. It is the inactive hormone. It must be converted to T3. I think what you really mean to ask, is supplementing with T3 better than supplementing with T4 to burn bodyfat? That depends. If your T4 to T3 conversion already sucks then adding in more T4 doesn't improve it. You may just produce more rT3 or T2, which exactly what you don't want it to do. If your body is chewing through T4 like it is a PES dispenser, i.e. you are on a lot of GH, then adding in extra T4 is the most beneficial.