T4 (Thyroxine), Free
The T4 Free Test measures the level of free thyroxine (T4) in the body. T4 is a hormone produced by the thyroid gland that helps regulate metabolism and body temperature. T4 can be bound to protein or circulate “freely” (unbound). The American Thyroid Association recognizes free T4 as a more accurate measurement of T4 than T4 bound to proteins (which can be impacted by protein levels).
Test results may take 1-2 business days.
Choose the test you want (be sure to pick the laboratory you want to use).
Pay by credit card or PayPal®.
You pay directly and we do not bill your insurance.
(Note: to preserve lowest possible per test pricing, a single $10.00 lab fee is applied to one or more blood tests. You will not incur any additional charges at the lab.)
After purchasing your testing you will receive an email with your lab requisition. Bring this form to the laboratory.
NOTE: Be sure to visit the appropriate laboratory!
If you choose LabCorp only visit a
Labcorp location.
If you choose Quest Diagnostics
only visit a Quest location!
No appointment is needed, but making one can minimize your wait time.
Click here for HOURS & APPOINTMENTS
If you have selected the option to have an At Home Test Kit delivered to you, you will receive your test kit in the mail within 5 to 7 business days. (Not all tests are available as At Home Test Kits.)
We’ll email you when your results are ready. Sign into your account to view and download your result reports.
Certain result values may prompt a phone call from our ordering provider to ensure the patient is aware of their result.
FT4, thyroxine
Associated Categories
Frequently Ordered Together
Measures the amount of thyroid-stimulating hormone TSH, Free T3, Free T4, T3 Uptake, T4, T7, T3 Total and Thyroid Peroxidase Antibody (TPO).
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