I had that same problem when I used losal Iodine awhile back.Then went onto the iodoral and did not have any pain with it. Then after awhile the iodoral quit working for me (sub-clinical hypothyroid) no matter how much I upped the dosage. Then I figured out I had adrenal fatigue. I think what happens is when you are low cortisol the Iodine cannot get to the receptors. I started on adrenal cortex and went back to iodoral and can tell its working. I am on only 1 to 1 1/2 iodoral a day. I would suggest you go to Dr.Lams site and read up on adrenal fatigue. Hope this helps.