---
title: "TBG (Thyroxine-Binding Globulin) Test: What It Measures"
description: "It measures the main thyroid hormone carrier protein to clarify confusing total T4/T3 results, with easy ordering and Quest-network labs via Vitals Vault."
canonical: "https://www.vitalsvault.com/biomarkers/tbg-thyroxine-binding-globulin"
last-updated: 2026-08-22
---

# TBG (Thyroxine-Binding Globulin) Test: What It Measures

> It measures the main thyroid hormone carrier protein to clarify confusing total T4/T3 results, with easy ordering and Quest-network labs via Vitals Vault.

---

Canonical HTML: https://www.vitalsvault.com/biomarkers/tbg-thyroxine-binding-globulin
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