A group of metabolites derived from

thyroxine File:Thyroid_system.svg, upright=1.5, The thyroid system of the thyroid hormones T3 and T4 rect 376 268 820 433 Thyroid-stimulating hormone rect 411 200 849 266 Thyrotropin-releasing hormone rect 297 168 502 200 Hypothalamus rect 66 216 38 ...

and

triiodothyronine Triiodothyronine, also known as T3, is a thyroid hormone. It affects almost every physiological process in the body, including growth and development, metabolism, body temperature, and heart rate. Production of T3 and its prohormone thyrox ...

via the peripheral enzymatic removal of iodines from the thyroxine nucleus. Thyronine is the thyroxine nucleus devoid of its four iodine atoms.Pubchem
Compound summary, L-thyronine

References

{{Thyroid hormone intermediates Amino acids