Thyroxine (T4) is almost entirely bound to proteins (like Thyroxine-Binding Globulin) as it travels through your bloodstream.
- Bound T4: Represents about 99.9% of the total. It is inactive and serves as a reservoir.
- Free T4: The tiny fraction that is unbound and active. A Total T4 test measures both, providing a broad look at how much hormone your thyroid is capable of producing.
₹300.00