triiodothyronine

noun

tri·​io·​do·​thy·​ro·​nine ˌtrī-ˌī-ə-dō-ˈthī-rə-ˌnēn 

: an iodine-containing hormone C₁₅H₁₂I₃NO₄ that is an amino acid derived from thyroxine

called also T3

Examples of triiodothyronine in a Sentence

Recent Examples on the Web

This hormone sends signals to the thyroid to create the hormones triiodothyronine (T3) and thyroxine (T4). —Dr. Roshini Raj, Health, 14 June 2024

These include thyroid-stimulating hormone, or TSH, which stimulates the thyroid gland to release two other hormones: triiodothyronine, or T3, and thyroxine, or T4. —Brad Reisfeld, Discover Magazine, 12 Feb. 2024

The hormones that the thyroid gland makes — triiodothyronine, or T3, and thyroxine, or T4 — affect all aspects of your metabolism. —Mayo Clinic News Network, chicagotribune.com, 4 Oct. 2019

Your thyroid produces hormones like thyroxine and triiodothyronine, which influence many of your body’s systems, according to the Mayo Clinic. —Zahra Barnes, SELF, 16 Jan. 2018

Word History

Etymology

tri- + iod- + thyronine an amino acid of which thyroxine is a derivative

First Known Use

1952, in the meaning defined above

Medical Definition

triiodothyronine

noun

tri·​io·​do·​thy·​ro·​nine ˌtrī-ˌī-əd-ō-ˈthī-rə-ˌnēn 

: a crystalline iodine-containing hormone C₁₅H₁₂I₃NO₄ that is an amino acid derived from thyroxine and is used especially in the form of its soluble sodium salt C₁₅H₁₁I₃NNaO₄ in the treatment of hypothyroidism and metabolic insufficiency

called also liothyronine, T3