THOUGH IODINE IS A CONSTITUENT OF THYROID HORMONE IT IS THE FASTEST ACTING THYROID INHIBITOR. IT IS REDUCED IN THE INTESTINES TO IODIDE AND THE RESPONSE TO IODINE OR IODIDES IS IDENTICAL. THE GLAND IF ENLARGED SHRINKS, BECOMES FIRM AND LESS VASCULAR. THE THYROID STATUS STARTS RETURNING TO NORMAL AT A RATE COMMENSURATE WITH COMPLETE STOPPAGE OF HORMONE RELEASE FROM THE GLAND. THE GLAND ITSELF INVOLUTES AND COLLOID IS RESTORED. WITH DAILY ADMINISTRATION. PEAK EFFECTS ARE SEEN IN 10-15 DAYS AFTER WHICH THYROID ESCAPE OCCURS AND THYROTOXICOSIS MAY RETURN WITH GREATER VENGENCE. IMPORTANT ACTION IS INHIBITION OF HORMONE RELEASE THYROID CONSTIPATION. IODINE HAS A POWERFUL BACTERICIDAL ACTION AND ACTIVE AGAINST FUNGI, VIRUSES, PROTOZOA, CYSTS, AND SPORES.