The short answer
T3, Free & Total (Triiodothyronine) measures Free T3 and Total T3 from a standard blood draw. At TestWell it costs $33.99 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
$33.99
+ $6 lab processing fee
Triiodothyronine (T3) is the thyroid hormone that actually drives metabolism at the cellular level. Total T3 measures everything in circulation, most of it bound to carrier proteins; Free T3 measures the small unbound fraction that is biologically active. Read together, they distinguish a genuine change in T3 production or T4-to-T3 conversion from a shift in binding proteins, and they help explain hypothyroid or hyperthyroid symptoms when TSH and T4 alone don't tell the whole story. Most useful as part of a full thyroid workup rather than as a first-line screen.
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 T3, Free & Total (Triiodothyronine) 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 T3, Free & Total (Triiodothyronine) test costs $33.99 at TestWell — $39.99 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 $160.00 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) | $33.99 | $39.99 | Includes the one $6 lab processing fee, charged once per order |
| Hospital outpatient lab, self-pay (typical) | $160.00 | $160.00 | 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
$33.99
+ $6 lab processing fee at checkout
No insurance needed · HIPAA compliant
Frequently ordered together
Customers who ordered T3, Free & Total (Triiodothyronine) also added these for a more complete health picture.
Not sure where to start?
T3, Free & Total (Triiodothyronine)
$33.99