Resin T3 uptake

This lab test can help your doctor interpret other tests when evaluating thyroid function. This test is not used very much anymore.

Resin T3 uptake Overview

Reviewed: April 22, 2014

Resin T3 uptake test measures the level of proteins that carry thyroid hormone in the blood. This can help your health care provider interpret the results of T3 and T4 blood tests. However, because the free T4 blood test is available, the resin T3 uptake test is rarely used anymore.

Resin T3 uptake is measured as a percentage. The normal range for resin T3 uptake is 24-37%.


Blood draw


Fasting is not required before the test

What the results mean

A higher T3 uptake means less thyroxine-binding globulin (TBG) is available possibly due to hyperthyroidism.

Decreased T3 uptake may indicate hypothyroidism.