Tiratricol is an orphan drug for use in combination with levothyroxine to suppress thyroid stimulating hormone in patients with well-differentiated thyroid cancer who are intolerant to adequate doses of levothyroxine alone. Tiratricol is a metabolite of the thyroid hormone triiodothyronine (T3) and has thyroid hormone activity.
Tiratricol is also marketed as a dietary supplement for weight-loss purposes. In November, 1999, the Food and Drug Administration (FDA) warned against consuming products containing tiratricol. This was based on reports of individuals using tiratricol developing side effects, such as fatigue, lethargy, profound weight loss and severe diarrhea. They were also found to have abnormal thyroid function tests. Further action by the FDA is being considered.
Tiratricol is also known as triiododothyroacetic acid, TRIAC, 3,5,3' -triiodothyroacetic acid and [4-(4-hydroxy-3-iodophenoxy) -3,5-di-iodophenyl]acetic acid. Its molecular formula is C14H9I3O4, and its molecular weight is 621.9 daltons.