Hospital
$120+
Other Labs
$35
TestWell
$22.99
T3 Uptake (also called T3 Resin Uptake or THBR) is an indirect measure of how much thyroid-binding protein in your blood is available to carry thyroid hormones. It does not measure T3 hormone levels directly. Instead, it helps determine whether abnormal total T3 or T4 levels are due to actual thyroid dysfunction or simply changes in binding protein levels (which can be affected by pregnancy, estrogen therapy, liver disease, or certain medications). When combined with Total T4, the T3 Uptake allows calculation of the Free Thyroxine Index (FTI), providing a more accurate assessment of thyroid status.
Sample Type
Blood draw
Fasting
Not required
Results In
1–3 business days
Performed By
Quest
1 biomarker tested
Your T3 Uptake results will include values for each of the 1 biomarker tested, along with reference ranges. Results are reviewed by a licensed physician before being released to your secure portal.
If any values fall outside the normal range, your report will include guidance on what that may mean and recommended next steps. You'll receive an email notification when your results are ready, typically within 1–3 business days.
Typical reference range layout
Lab reports show where your value sits relative to established reference intervals—your physician interprets this in context for you.
No fasting or special preparation required.
TestWell Price
$22.99
No insurance needed · HIPAA compliant
Frequently ordered together
Customers who ordered T3 Uptake also added these for a more complete health picture.
Measures total testosterone levels — the starting point for evaluating hormonal health in men and women.
$33.99
The definitive vitamin D test — an estimated 42% of American adults are deficient.
$41.99
General inflammation marker — elevated in infections, autoimmune conditions, and chronic disease.
$19.99
T3 Uptake
$22.99