Free triiodothyronine (free T3) is the biologically active form of the thyroid hormone triiodothyronine circulating in the bloodstream unbound to proteins. It is derived primarily from the peripheral conversion of thyroxine (T4) and plays a critical role in regulating metabolism, growth, and development by influencing cellular energy production, thermogenesis, and gene expression. Because only the free, unbound fraction of T3 can enter cells and exert its effects, measuring free T3 levels provides a more accurate assessment of thyroid hormone activity compared to total T3 levels.
In clinical and research settings, free T3 is used as a key biomarker to evaluate thyroid function, particularly in diagnosing hyperthyroidism and certain cases of hypothyroidism. It is especially useful when symptoms of thyroid dysfunction are present but total T3 and T4 levels are normal, or when thyroid hormone resistance is suspected. Free T3 measurement also aids in monitoring treatment efficacy in thyroid disorders and in understanding metabolic disorders related to thyroid hormone imbalances. In research, free T3 is studied to elucidate thyroid hormone regulation mechanisms and their impact on various physiological and pathological conditions.
This product is manufactured in USA by Eagle Biosciences.