Thyroxine-Binding Globulin (TBG)
Hormone markersWhat the test generally measures, and what to ask about it.
Longetic keeps every lab and record you’ve had organized and easy to find, so your own Thyroxine-Binding Globulin (TBG) values sit together on one chart and you walk into your next appointment prepared.
What is Thyroxine-Binding Globulin (TBG)?
The main protein that carries thyroid hormone through your blood.
Thyroxine-binding globulin is the protein that transports most of your thyroid hormone, keeping a reserve that tissues can draw on. Higher levels can be associated with pregnancy, estrogen use or certain inherited patterns, while lower levels can be associated with some illnesses, steroid use or an inherited deficiency. TBG mainly matters when it seems to be skewing thyroid hormone readings, so it is a specialized test used to explain confusing results rather than a routine one.
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