For what its worth, I have never run t4, or t3 . I have been on HGH for over year now. I can tell you I lost plenty of body fat, became very vascular, and my skin has changed. I also have run it with currently with IGF-LR3, along with different combinations of gear. Good luck, do not sweat the t3, t4 issue. This web site has had a ton of data on it that I have found to be INVALUABLE ! Good luck !