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Free T3

$32.20
LabcorpNo fasting2-4 business days

Plus a $12 blood draw fee, charged once per order. Free when your order includes a bundle.

Sample
Blood draw
Preparation
No fasting needed.
Results in
2-4 business days after your sample reaches the lab

Tests are ordered by an independent licensed physician. This service does not replace care from your own doctor. Talk with a healthcare professional about your results.

This test measures free T3, the most biologically active thyroid hormone.

It’s often ordered alongside TSH and free T4 when thyroid symptoms persist despite a normal TSH. If you take biotin supplements, ask your doctor whether to pause them before your draw — biotin can interfere with this kind of test.