The short answer
T4, Free & Total (Thyroxine) measures Free T4 and Total T4 from a standard blood draw. At TestWell it costs $22.99 plus a $6 lab fee, needs no fasting, and results post in 1–3 business days. Physician-authorized with no doctor's visit or insurance needed; draw at Quest or Labcorp.
TestWell Price
$22.99
+ $6 lab processing fee
Thyroxine (T4) is the main hormone the thyroid produces, and it circulates in two forms: bound to carrier proteins and free. Total T4 measures the whole pool and reflects overall thyroid output; Free T4 measures only the unbound, biologically active fraction that tissues can actually use. Ordering both together separates a true change in thyroid output from a change in binding proteins — which shift with estrogen, pregnancy, oral contraceptives, liver disease and some medications — and gives a fuller picture than either value alone. Typically ordered alongside TSH when thyroid function is being established or monitored.
Thyroid testing measures the hormones that regulate metabolism, energy, body temperature, weight, and mood — identifying both overactive and underactive thyroid conditions.
Anyone with fatigue, weight changes, mood changes, hair loss, cold/heat intolerance, irregular cycles, or family history of thyroid disease.
Sample Type
Blood draw
Fasting
Not required
Results In
1–3 business days
Performed At
Quest or Labcorp
Your T4, Free & Total (Thyroxine) results will include values for each of the 2 biomarkers tested, along with reference ranges. Results are reviewed by a licensed physician before being released to your secure portal.
If any values fall outside the normal range, your report will include guidance on what that may mean and recommended next steps. You'll receive an email notification when your results are ready, typically within 1–3 business days.
Typical reference range layout
Lab reports show where your value sits relative to established reference intervals—your physician interprets this in context for you.
No fasting required. Biotin supplements can interfere with thyroid assays — skip them for 48 hours before your draw if possible.
A T4, Free & Total (Thyroxine) test costs $22.99 at TestWell — $28.99 all-in when ordered alone, because the $6 lab processing fee is charged once per order, with no draw fee or physician fee added. Hospital outpatient labs typically bill around $150.00 self-pay for the same test, and often more. With insurance, what you pay depends on your deductible and your plan's negotiated rate; TestWell's price is fixed before the draw and is HSA/FSA-eligible.
| Where you order | Price | One test, all-in | Notes |
|---|---|---|---|
| TestWell (drawn at Quest or Labcorp) | $22.99 | $28.99 | Includes the one $6 lab processing fee, charged once per order |
| Hospital outpatient lab, self-pay (typical) | $150.00 | $150.00 | Reference figure; hospital charges vary widely by facility and are often higher |
Competitor prices are read from the linked public pages and re-checked regularly; the labs' sites may add taxes or change prices without notice.
TestWell Price
$22.99
+ $6 lab processing fee at checkout
No insurance needed · HIPAA compliant
Frequently ordered together
Customers who ordered T4, Free & Total (Thyroxine) also added these for a more complete health picture.
Not sure where to start?
T4, Free & Total (Thyroxine)
$22.99