Total T3
Total T3 measures both free and protein-bound triiodothyronine. Like total T4, it is affected by changes in binding proteins and is less preferred than free T3 for routine thyroid assessment. It can still be useful in diagnosing T3 toxicosis, a form of hyperthyroidism where free T3 rises disproportionately to T4.
Optimal range: who says what
No institution or named practitioner we track states an optimal target for Total T3. How we verify ranges.
- General guidance, no named sourceMid-referenceNo separate optimal; free T3 is the more meaningful measure
- Lab reference interval80-200 ng/dLWhat a lab report flags against. A lab interval is not an optimal target.
3 providers include this
Thyroid Function
Why Total T3 matters
Active thyroid hormone. Measures both protein-bound and free T3. Affected by binding protein levels. Used with Free T3 for complete thyroid assessment.
Which Providers Test Total T3?
Vitality Blueprint Elite is both the cheapest ($700/year) and the most comprehensive (138 biomarkers) panel that includes Total T3.
3 panels that include it, cheapest first
| Provider | Annual Cost | Total Biomarkers | $/Biomarker |
|---|---|---|---|
| $700 | 138 | $5.07 | |
| $895 | 100+ | $8.95 | |
| $1950 | 130+ | $15.00 |
$/Biomarker is annual cost divided by the panel's advertised biomarker count, not the price of this one test. We track 23 blood test providers (32 plans); 21 of those plans are itemized marker by marker. Compare all of them.
18 itemized panels do not include Total T3
Superpower · WHOOP Advanced Labs · Labcorp OnDemand · Life Extension Elite · Everlywell · Mito Health · InsideTracker · Function Health · Marek Health Base · Marek Health Comprehensive · Blueprint · Empirical Health · Oura Health Panels · SiPhox Health · Hims Labs · Healthspan · Vitality Blueprint Standard · Ultrahuman Blood Vision Annual
11 providers not itemized in our matrix
We have not itemized these marker by marker (some sell tests one at a time), so this page cannot say whether they offer Total T3. Check with them directly.
Life Extension Standard · Quest Health · Ultrahuman Blood Vision · Lifeforce · Hundred Health · Personalabs · Walk-In Lab · HealthLabs · WHOOP Specialized Panels · Marek Health Essential · Vitality Blueprint Upload
Experts discussing Total T3
Podcast episodes where clinicians and researchers cover this marker in depth. Curated by hand; an episode is listed only when the marker is a substantial topic, not a passing mention.
- How to Control Your Metabolism by Thyroid & Growth HormoneDisclosure: Huberman Lab has been sponsored by Function Health, which appears in our blood-test comparisons.
Frequently Asked Questions
What is the optimal range for Total T3?
No institution or named practitioner we track states an optimal target for Total T3. General guidance without a named source: Mid-reference (No separate optimal; free T3 is the more meaningful measure). Lab reference interval: 80-200 ng/dL. That is what a lab report flags against, not an optimal target.
Which blood test providers include Total T3?
3 of the 21 blood testing panels we itemize marker by marker include Total T3 in their panels. This biomarker has limited availability.
Related: YouBoost rates lifestyle and supplement interventions by evidence.
Medical Disclaimer
This information is for educational purposes only and is not medical advice. Always consult with a qualified healthcare provider about your specific health needs.
Last reviewed Aug 26, 2026 · First published Nov 30, 2025