What alternative medicine can help with underactive thyroid?
I am not aware of any other supplement for underactive thyroid apart from replacing the thyroid hormone: Thyroxine. See the wiki page. A synthetic thyroid supplement can be prescribed, which the patient must take daily to replace the missing hormone. The American Thyroid Association cautions against taking herbal remedies, and warns that taking too much iodine can actually worsen both hypothyroidism and hyperthyroidism.