T3 Uptake details
Description
T3 uptake is an older laboratory test that doesn't directly measure T3 or T4, but instead assesses how much binding capacity is available on your thyroid hormone-carrying proteins. It's used, together with total T4, to calculate the Free Thyroxine Index (FTI), an older method of estimating free (active) T4 levels. Because direct free T4 assays are now widely available, accurate, and simpler to interpret, T3 uptake and FTI are used far less often today, though they're still occasionally reported by certain labs or in specific clinical situations.
Optimal & Reference range
T3 Uptake
%- Low
- Below optimal
- Optimal
- High
- Optimal range
- 27 - 35
- Reference range
- 22 - 35
- Out of range
- <22 or >35
Interpretation
- Low: Your result is below the reference range. Discuss it with your healthcare provider, who can interpret it alongside your symptoms and other results.
- Below optimal: Your result is within the reference range, but below the range we consider optimal.
- Optimal: Your result is within the optimal range.
- High: Your result is above the reference range. Discuss it with your healthcare provider, who can interpret it alongside your symptoms and other results.
- These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Blood tests with T3 Uptake
Explore available tests to better understand your results and gain deeper insights into your health.
Single marker
T3 Uptake
$6.49
T3 Uptake is a test that indirectly estimates the number of available binding sites on thyroid-binding proteins, primarily thyroid-binding globulin (TBG). It is used alongside total T4 to calculate the Free Thyroxine Index (FTI), helping to assess thyroid function and differentiate between thyroid and binding protein abnormalities.
- T3 Uptake An older test used, together with total T4, to estimate free thyroid hormone levels by assessing binding protein capacity.
Panel
Thyroid Panel (T4 Total, T3 Uptake, T7)
$8.99
For diagnosis of hypothyroidism and hyperthyroidism.
- T3 Uptake An older test used, together with total T4, to estimate free thyroid hormone levels by assessing binding protein capacity.
- T4, Total Measures total thyroxine (T4), including both bound and unbound hormone, used in thyroid function evaluation.
- Free T4 Index (T7)
Thyroid Panel with Thyroid-Stimulating Hormone (TSH)
$26.99
The Thyroid Panel assesses 4 key markers related to thyroid function. It helps evaluate overall thyroid health and is commonly used to diagnose conditions like hypothyroidism, hyperthyroidism, and monitor thyroid therapy.
- T3 Uptake An older test used, together with total T4, to estimate free thyroid hormone levels by assessing binding protein capacity.
- T4, Total Measures total thyroxine (T4), including both bound and unbound hormone, used in thyroid function evaluation.
- Thyroid-Stimulating Hormone (TSH) A pituitary hormone that signals your thyroid to produce hormone. The primary screening test for both underactive and overactive thyroid conditions.
- Free T4 Index (T7)