Description
Produced by the follicular cells of the thyroid gland under the influence of thyroid-stimulating hormone (TSH). It is the fraction of thyroxine not bound to blood proteins and provides most of the spectrum of biological effects of thyroid hormones. Its main functions are aimed at stimulating metabolic processes in the body (vitamin A is synthesized in the liver with its participation, it accelerates protein synthesis, controls heat production, and oxygen consumption rate). In pregnant women, the concentration of free thyroxine increases, reaching a maximum in the 3rd trimester. Determination of free T4 is used as a reliable diagnostic test to assess thyroid function. The study is recommended to be performed in conjunction with the determination of thyroid-stimulating hormone (TSH).
It is recommended to take the test in the morning hours. For the most informative results, check with your doctor for the optimal time to take the test.
Period of execution
By 9 hours. The specified time does not include the day of biomaterial collection
Biomaterial type