The Free T3 test measures the level of unbound (active) triiodothyronine (T3) in the blood. T3 is a key thyroid hormone that regulates metabolism, energy production, body temperature, and heart rate. Measuring the free (active) form provides insight into the hormone that is available for use by the body.
This test is commonly used as part of a comprehensive thyroid evaluation, especially when symptoms of thyroid imbalance such as fatigue, weight changes, heat or cold intolerance, or heart rate changes are present. Free T3 results are often interpreted alongside TSH and Free T4 to assess overall thyroid function.
T3, Free
The Free T3 test measures the level of unbound (active) triiodothyronine (T3) in the blood. T3 is a key thyroid hormone that regulates metabolism, energy production, body temperature, and heart rate. Measuring the free (active) form provides insight into the hormone that is available for use by the body.
This test is commonly used as part of a comprehensive thyroid evaluation, especially when symptoms of thyroid imbalance such as fatigue, weight changes, heat or cold intolerance, or heart rate changes are present. Free T3 results are often interpreted alongside TSH and Free T4 to assess overall thyroid function.
