Liothyronine the preparation of thyroid hormones. Synthetic levorotatory isomer of thyroxine. In small doses, has an anabolic effect. In moderate doses stimulates growth and development increases the demand of tissues in oxygen, stimulates the metabolism of proteins, fats and carbohydrates, stimulates the cardiovascular system and Central nervous system. In high doses inhibits the production TRH hypothalamus and TSH from the pituitary gland.