Thyroid
Free Thyroxine Index
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Thyroid
T3 Uptake
T3 Uptake isn’t a direct measure of T3—it reflects how much thyroid-binding protein (mostly TBG) is available in your blood. High uptake means less binding protein (more free hormone available), and low uptake means more binding protein (less free hormone). It’s mainly used to help calculate Free Thyroxine Index (FTI) and to interpret T4 levels more accurately. Useful for spotting binding protein imbalances from estrogen, liver issues, or stress.
- Unit
- %
- Health impacts
- Energy · Fat Loss · Thyroid
In your dashboard
Your trend, against your optimal range.
Example data · how your trend would appear once you test
At every level
What we'd do at any value.
Exploring
31.5%
LowOptimal 24.0–39.0High
In your optimal zone
Habits that hold this position.
No specific guidance for this zone yet. We're working on it and will update this soon.
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