T3 Uptake
Specialistalso thbr
What it isA legacy test that indirectly measures available thyroid-binding protein capacity by competing radiolabeled T3 against the patient's own thyroid hormones.
DoesProvides one of the inputs into the legacy Free T4 Index calculation.
GoodA mid-range value with normal Free T4 indicates balanced transport protein levels.
BadLargely superseded by direct Free T4 measurement.
- Standard
- 22–35%.
- Optimal
- 26–32% (narrow target)
- Modifiers
- Estrogen, pregnancy, and liver disease shift binding proteins.
How to optimize
- Lifestyle
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- Diet
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- Supplements
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- Peptides
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- Drugs
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Reference ranges are general adult lab norms; optimal ranges are editorial picks from the longevity literature — not medical advice. Always interpret results with your physician.
within Thyroid