liothyronine

Triiodothyronine also known as T3, is a thyroid hormone. It affects almost every physiological process in the body, including growth and development, metabolism, body temperature, and heart rate. Together with thyroxine (T4), T3 exerts a potent influence on the basal metabolic rate. T3 is synthesized from the tyrosine residues of thyroglobin and is found in the serum of normal individuals. Although T3 has a lower serum concentration than T4, it is 5 to 10 times more active.