Resmetirom is an orally administered small molecule liver targeted thyroid hormone receptor beta (THR β), which is the most expressed thyroid receptor in the liver and can promote cholesterol metabolism and reduce fat production, thereby improving lipid abnormalities in patients with non-alcoholic fatty liver disease (NASH). Excessive thyroid hormones can not only specifically bind to THR β in the liver, but also to THR α, causing adverse reactions in the heart and bones. Therefore, specific THR β agonists can regulate lipid metabolism and to some extent avoid the side effects of thyroid hormones on the heart and bones.