T4 Thyroxine, Total and Free Serum - T4FT4

This comprehensive test measures both free (unbound) and total (bound + unbound) thyroxine (T4) in the blood — giving a full view of thyroid hormone status, including how much hormone is available to tissues and how much is held in reserve.

It’s especially useful when thyroid-binding protein levels might be altered (such as in pregnancy, liver disease, or hormone therapy), and when you want a more complete assessment of thyroid function than a standard Free T4 or Total T4 alone.