Once a person needs thyroid medicine to improve symptoms of decreased thyroid system function, or low thyroid blood tests for that matter, s/he will always need thyroid medicine for the rest of her/his life.
FALSE. Even glandular insufficiencies of the thyroid system can be temporary, making it possible for people to be weaned off thyroid medicine sometimes, with their glandular function coming back up to normal. And people without glandular insufficiencies are particularly easy to wean off T3 therapy successfully after their symptoms have resolved.