The molecular structure of Thyroxine (T4) hormone can be visualized as a horse. (1) This simple visual diagram can help you “see” what is invisible and mysterious — how T3 and other forms of thyroid hormone are created from T4. Imagine a molecule with two circles and a tail as the body of the horse. Next, put four iodine atoms around the two circles. Put two iodines on the head circle and two iodines on the body circle. Now you’ve got the thyroxine hormone — also known as “tetra-iodothyronine” (tetra = four) because it has four iodine atoms. However, analogies …