The short answer
Measures total triiodothyronine (T3), bound and free — the thyroid hormone that rises first in many cases of an overactive thyroid, measured from a standard blood draw. At TestWell it costs $24.99 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
$24.99
+ $6 lab processing fee
Total T3 measures all of the triiodothyronine in your blood — the roughly 99% carried on binding proteins plus the small free fraction. T3 is the more active thyroid hormone, and in hyperthyroidism it often rises earlier and further than T4, so total T3 is part of the standard work-up when TSH is low: it distinguishes ordinary Graves' disease or toxic nodules from the less common 'T3 toxicosis' in which only T3 is elevated, and it helps gauge severity. It is less useful for diagnosing an underactive thyroid, where T3 tends to stay normal until late. Because total T3 counts protein-bound hormone, anything that changes binding proteins — pregnancy, estrogen, oral contraceptives, liver disease, some medications — shifts the result without changing thyroid function, which is why clinicians read it alongside TSH and free T4 (and sometimes free T3).
Sample Type
Blood draw
Fasting
Not required
Results In
1–3 business days
Performed At
Quest or Labcorp
1 biomarker tested
Your T3, Total (Triiodothyronine) results will include values for each of the 1 biomarker 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. Stop high-dose biotin supplements at least 2 days before the draw (biotin interferes with thyroid assays). If you take thyroid medication, take your dose after the blood draw.
A T3, Total (Triiodothyronine) test costs $24.99 at TestWell — $30.99 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 $120.00 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) | $24.99 | $30.99 | Includes the one $6 lab processing fee, charged once per order |
| Hospital outpatient lab, self-pay (typical) | $120.00 | $120.00 | Reference figure; hospital charges vary widely by facility and are often higher |
Lab test codes: Quest test code 859 · Labcorp test no. 002188 · BioReference code 0150-3. Competitor prices are read from the linked public pages and re-checked regularly; the labs' sites may add taxes or change prices without notice.
Compare more: Quest Diagnostics price list · Labcorp price list · Quest vs Labcorp · Lab test price checker
TestWell Price
$24.99
+ $6 lab processing fee at checkout
No insurance needed · HIPAA compliant
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T3, Total (Triiodothyronine)
$24.99