About this test
Additional Information
Reverse triiodothyronine (rT3) is an isomer of triiodothyronine (T3) with no demonstrated biological activity.1,2 The majority of rT3is produced through peripheral enzymatic monodeiodination of T4 at the 5 position of the inner ring of the iodothyronine nucleus of thyroxine (T4). A lesser amount of rT3 is secreted directly by the thyroid gland. Reverse T3 is biologically inactive and does not stimulate thyroid hormone receptors.
