The two most prominent hormones produced by the thyroid are thyroxine (T4) and triiodothyronine (T3). But there are others involved in maintaining a healthy thyroid and ultimately a healthy body. One such hormone that is wrongly invalidated by many endocrinologists is reverse triiodothyronine (Reverse T3). Because of inadequate appreciation or understanding of the impact Reverse T3 has on the body, many have been left to unduly suffer from a thyroid imbalance.
Reverse T3 is the mirrored inactive form of T3 and is instrumental in keeping thyroid hormone levels in balance. Without the presence of Reverse T3 in one’s system there is great risk that their T3 levels reach dangerously high levels resulting in a severe case of hyperthyroidism (an overactive thyroid frequently caused by excess T3). Alternatively, too much Reverse T3 overly inhibits T3’s ability to provide energy and oxygen to one’s cells resulting in reduced metabolic function on a cellular level. Reverse T3 and T3 compete for the same receptors throughout the body. If there is a greater prevalence of Reverse T3 in one’s system, it will effectively block active thyroid hormone from reaching cells. Maintaining the appropriate ratio of T3 to Reverse T3 helps keep the body running smoothly.
As an effective T3 inhibitor, Reverse T3 helps the body maintain a proper balance of active thyroid. Not only does it block receptor sites but it influences conversion of T4 into other hormones. Studies have found that Reverse T3 can be 100 times more effective at reducing the conversion of T4 into T3 than Propylthiouracil (PTU), a treatment option for those with hyperthyroidism. Although this regulatory action is useful for maintaining proper thyroid hormone levels, if Reverse T3 is overproduced it can cause severe hypothyroidism. Those who have hypothyroidism generally see an increase in symptom severity when there is an overabundance of Reverse T3 in their bloodstream.