What is the best thing to take for my low Thyroid?

I know it is all about the Iodine with the low Thyroid. I have taken meds for years now and my levels have not changed. After about a year now of slowly taking myself off the medicine for low Thyroid. I still feel fine it has been a year. I would like to change to a more natural source. If you have any over the counter suggestions I would be most grateful. Thanks a bunch..