t3 is a bit of a mind fuck for me. I found myself getting aggressive with it, and thinking "hey 50 mcg is working okay so let's bump it up!" and I kept going up and up, assuming it would keep getting me leaner and leaner. I wasn't noticing any muscle "loss" per se so I wasn't too scared of a higher dose. After awhile I took a step back and assessed my progress, and felt like I really wasn't losing as much fat as I feel I should be for the dose I was taking and how restricted my diet was. My diet was absolutely on point with a pretty aggressive carb cycle, and I just felt like I wasn't really getting leaner and also just kinda flat.
I dropped the dose by 25mcg every 3 days back down to 50-75 and voila, fat is melting off and I look much better. I know scientifically this might not make sense, but it felt like my food was just going to waste as I wasn't eating much and the high t3 must have just burned it all off, so my body wasn't really aborbing or processing much. Just kinda stalled out.
I think what I'm trying to say is, if you feel you stalled out, try tapering up and down a bit as I felt like the change re-kicked in progress.