Thyroid Binding Globulin

Aka TBG Made in the liver. TBG is a protein that binds and carries T4 and T3 in the blood. There are also other proteins that carry thyroid hormones ie Albumin and Transthyretin. Especially useful where T4 and T3 don’t have accompanying thyroid symptoms as levels can also be related to oestrogen, corticosteroids, and liver function.