First of all, it is a very bad idea to use T3 for fat loss. You should never mess with your thyroids, because it is a very delicate gland, and you can end up with much worse results. Not long ago, I have personally seen the case of a lady who was taking it for fat loss. Everything went well in the beginning, and then she had a bad reaction to it, and had to stop using it. Ever since, she is gaining weight uncontrollably. All in all, you should never use thyroid meds without a proper prescription from your doc based on blood work.