The physiological actions of thyroid hormones are generated predominantly by T3, nearly all which (about 80%) is derived from T4 by deiodination in peripheral tissues. Synthetic T4 is equivalent in chemical construction into the T4 created within the human thyroid gland. Levothyroxine sodium has the molecular system C15H10I4NNaO4 ∙ xH2O, https://torzondarkweb.com/product/ovunal-sc-2000-iu/