I had a recent experience with Cytomel which lowered my TSH to 0.033, made me hyperthyroid and caused polyneuropathy (burning, pis/needles, aching pain) in my feet, legs and hands. My doc had lowered my levo by 20% back in Feb making me sick and hypothyroid. While trying to bring me out of my hypo state, he added 25mcg of Cytomel to my 0.137 levo. This rapidly caused neuropathy which we could not figure out at the time. I was sent to an endocrinologist and she had me stop Cytomel.