I have Hashimoto's and originally was put on synthroid. I felt better at first in some areas but then I began to feel like a Mack truck had run over me. Having problems with Hashi has also made me more and more allergic to odors, chemicals AND medicine, including synthroid. My Endo would not let me change to Armour or natural compounded thyroid. I found an Internal Medicine Doctor (female) that had come down with Hashi when in medical school. Through her first hand experience and searching for answers, she began to think outside the box. She prescribed natural compound thyroid for me and it did wonders. Unfortunately, she was in a car accident and died on the operating table. My life ended up in the care of another Endo who fought me as well. When I went back on synthroid, my body ached, muscles and joints hurt, I felt as though I had a sever case of the flu. Because of the symptoms, I was tested for Lupus. I found out through research that it could be the dyes in the synthroid that would cause allergic reactions. My Endo would not work with me to change even to Armour. I finally found a DO that also would use alternative medicine. We get along great and I am back on the natural compounds and feel much better. The dyes in the synthroid may be your culprit as well. Ninniet