The physiological actions of thyroid hormones are created predominantly by T3, nearly all of which (about 80%) is derived from T4 by deiodination in peripheral tissues. Synthetic T4 is equivalent in chemical construction into the T4 generated from the human thyroid gland. Levothyroxine sodium has the molecular system C15H10I4NNaO4 ∙ https://dominickhebwr.pointblog.net/about-xanax-bars-images-88906786