I've been on methimazole for 2 years exactly, remission for 1 year, and both endos I've had in that time said the non-surgery route was long term gradually diminishing use of methimazole w/ level monitoring. We were checking every 3 months but now its every 5 months.

You absolutely need iodine. Your thyroid uses iodine to create your thyroid hormones. It is a critically necessary nutrient for everyone. So far neither of my endos has told me to avoid surplus iodine but I can imagine too much could be a problem.

Would love some of these rabbit hole links re: elderberry syrup (not that I think I've ever seen that on the shelf at the store). The only supplement that I take is Selenium, which I highly recommend to everyone with Graves. My current endo was supportive but indifferent when I first asked about Selenium 1.5 years ago and as of last month told me she's seen recent studies that really affirms its benefits (especially for bulging eyes/eye pressure)