Liothyronine
"I have had  Hashimoto''s thyroiditis since 2003. I've been on Armour; I've been on Naturthroid and I've been on Synthroid.  it's been a struggle to keep the weight off or get any weight off.  I diet and exercise very stringently. You won't believe this:  25 mcg Synthroid and 5 mcg twice a day Lyothyroninr (Cytomel, or T-3) and the weight is practically falling off. I started on it May 13, 2016. That's 4 weeks. It started a few days ago and is I'm losing over a pound a day, sometimes 2. I wish I had known. See, my body makes antibodies to the desiccated porcine thyroid, as well as to my own. That's supposedly very rare. They were three times as high on Armour and Naturthroid as my own thyroid, and it's pretty high anyway."