I had a VERY bad experience with supporting the thyroid before my adrenal glands were ready. One doctor had put me on armour thyroid and a couple of iorodal per day.
It created a major adrenal crash. I called Dr Rind and he explained to me what what going on and told me to stop the armour thyroid and iodoral immediately or I was going to "fry my adrenal glands"
There is not a lot of information out there on it. Here is a link from Dr Rind, as well as some other links
When the adrenals are exhausted, the ability of the adrenals to handle the stress associated with normal bodily functions and energy requirements is often compromised. To enhance survival, the adrenals force a down-regulation of energy production.
I am starting back up with just Kelp. It seems to ge going OK. My adrenal glands are a lot stronger than they were back then.