---
title: "T3 Reverse (LC–MS/MS) Test: What It Measures"
description: "It measures reverse T3, an inactive thyroid hormone metabolite that can rise with illness or stress—order through Vitals Vault with Quest labs."
canonical: "https://www.vitalsvault.com/biomarkers/t3-reverse-lc-ms-ms"
last-updated: 2026-08-22
---

# T3 Reverse (LC–MS/MS) Test: What It Measures

> It measures reverse T3, an inactive thyroid hormone metabolite that can rise with illness or stress—order through Vitals Vault with Quest labs.

---

Canonical HTML: https://www.vitalsvault.com/biomarkers/t3-reverse-lc-ms-ms
- [llms.txt](https://www.vitalsvault.com/llms.txt)
- [sitemap.xml](https://www.vitalsvault.com/sitemap.xml)
- [Developer portal](https://www.vitalsvault.com/developers)