Natural remedies for hypothyroid, do they work? are they safe?

I have seen some stuff like "Raw Thyroid" and other natural remedies at health food stores and such, they have thyroid extracts of bovine (cow). I worry because it says that it may cause nervousness, rapid heartbeat, etc. Do these work and can a small dose cause nervousness and side effects? I am waiting to see an endocrinologist, but in the meantime it would be nice to see if I can feel better somewhat while I wait. Just for reference, my TSH was 5.3
How much iodine should I take? I saw on the bottle of Kelp it had all these warnings, I’m a little scared to take it until I know how much is safe. Thanks!