Free T3 and Free T4 Blood Test Panel

The Free T3 and Free T4 Blood Test Panel panel contains 2 tests with 2 biomarkers.

  • Free T3 - This test is used to diagnose hyperthyroidism and to clarify thyroid status in the presence of a possible protein binding abnormality.
  • Free T4 - For diagnosis of hypothyroidism and hyperthyroidism.

The following is a list of what is included in the item above. Click the test(s) below to view what biomarkers are measured along with an explanation of what the biomarker is measuring.

Also known as: Free T3, FT3, T3 Free

T3, Free

This test measures the amount of triiodothyronine, or T3, in the blood.

Also known as: Free T4, FT4, T4 Free

T4, Free

The free T4 test is not affected by protein levels. Since free T4 is the active form of thyroxine, the free T4 test is may be a more accurate reflection of thyroid hormone function.
*Process times are an estimate and are not guaranteed. The lab may need additional time due to weather, holidays, confirmation/repeat testing, or equipment maintenance.