It's my understanding that adrenal gland is important for t4 conversion. One of the best things is to increase salt, assuming it does not aggravate the edema. You might also try to get consistent selenium dosing daily from brewer's yeast. Egg yolks to help repair the cortex. Sweating and saunas over long period of time to get rid of the conversion disruptors. There are some pro iodine posters here on this forum too (look them up and read carefully). If you're on the right track you'll eventually be able to wean off of the cortex supplements.