--- title: Free T3 Test type: biomarker url: "https://www.test-well.com/biomarkers/free-t3" also_known_as: - free t3 - ft3 - triiodothyronine, free category: Thyroid units: - pg/mL order_price_usd: 30.99 order_item: Free T3 (Triiodothyronine) order_url: "https://www.test-well.com/tests/free-t3" reviewed_at: 2026-09-05 --- # Free T3 > Free T3 is measured with a standard blood draw; no fasting is needed. A typical reference range is 2.00 – 4.40 pg/mL. At TestWell it's $30.99 all-in as Free T3 (Triiodothyronine), results in 1–3 business days, drawn at Quest or Labcorp. An out-of-range result is a prompt to look closer, not a diagnosis. Also known as: free t3, ft3, triiodothyronine, free. ## Key facts | Fact | Value | | --- | --- | | Units | pg/mL | | Sample | Blood draw | | Fasting | Not required | | Results | 1–3 business days | | Price | $30.99 | | Labs | Quest or Labcorp · BioReference in NY/NJ | ## What does Free T3 measure? The active, unbound form of T3 — the most metabolically active thyroid hormone. ## What is the normal range for Free T3? | Population | Reference range | | --- | --- | | age 18+ | 2.00 – 4.40 pg/mL | Reference intervals differ slightly between labs; the range printed on your report is the one to interpret against. Ranges are usually set so 95% of healthy people fall inside them. ## How do you get tested for Free T3? | Order | Type | Price | Includes | | --- | --- | --- | --- | | [Free T3 (Triiodothyronine)](https://www.test-well.com/tests/free-t3) | Single test | $30.99 | This marker | | [Essential Thyroid Panel](https://www.test-well.com/tests/essential-thyroid-panel) | Panel | $49.99 | 3 tests | | [Hashimoto's Thyroid Panel](https://www.test-well.com/tests/hashimotos-thyroid-panel) | Panel | $97.99 | 3 tests | | [Complete Thyroid Panel](https://www.test-well.com/tests/thyroid-complete-panel) | Panel | $109.99 | 4 tests | | [Advanced Thyroid Panel](https://www.test-well.com/tests/advanced-thyroid-panel) | Panel | $129.99 | 7 tests | ## Quest vs Labcorp vs BioReference | Lab | Available | Price | Notes | | --- | --- | --- | --- | | Quest Diagnostics | Yes | $30.99 | Choose Quest at checkout; walk-in patient service centers in every state TestWell serves outside NY and NJ. | | Labcorp | Yes | $30.99 | Choose Labcorp at checkout; walk-in patient service centers in every state TestWell serves outside NY and NJ. | | BioReference (NY & NJ) | Yes | $32.99 | New York and New Jersey orders route here automatically — state rules keep Quest and Labcorp from accepting self-ordered draws. | - [What a high Free T3 means (causes, symptoms, next steps)](https://www.test-well.com/biomarkers/free-t3/high) - [What a low Free T3 means (causes, symptoms, next steps)](https://www.test-well.com/biomarkers/free-t3/low) ## Common questions about Free T3 ### Do I need a doctor's order to test my free t3? No. TestWell's licensed physician network reviews and approves your order — usually within minutes. You can place an order online without an in-person visit or a referral from your own doctor. ### How long does it take to get Free T3 results? Most Free T3 results are available in 1–3 business days after your specimen arrives at the lab. You'll get an email the moment your results are ready, with everything viewable in your TestWell portal. ### How much does a Free T3 test cost? Our Free T3 (Triiodothyronine) starts at $30.99. That's the all-in price — no copays, no insurance hoops, no surprise bills. HSA and FSA cards are accepted. ### Do I need to fast before my Free T3 test? Fasting is not required for the Free T3 test. You can have your blood drawn any time of day. ### Which lab will process my Free T3 test? Your test will be processed by Quest Diagnostics, Labcorp, or BioReference depending on which is closest to you and which lab carries the test. All three are CLIA-certified and trusted by hospitals nationwide. You'll choose your lab during checkout from 4,000+ locations. ## Sources - [Mayo Clinic Labs](https://www.mayocliniclabs.com/test-catalog/overview/8579) - [MedlinePlus (NIH) — Triiodothyronine (T3) Tests](https://medlineplus.gov/lab-tests/triiodothyronine-t3-tests/) ## Related biomarkers - [TSH](https://www.test-well.com/biomarkers/tsh) - [Free T4](https://www.test-well.com/biomarkers/free-t4) - [Reverse T3](https://www.test-well.com/biomarkers/reverse-t3) - [TPO Antibodies](https://www.test-well.com/biomarkers/tpo-antibodies) - [Thyroglobulin Antibodies](https://www.test-well.com/biomarkers/thyroglobulin-antibodies) - [Reference range lookup tool](https://www.test-well.com/tools/reference-range-lookup) - [Lab unit converter](https://www.test-well.com/tools/lab-unit-converter) - [All biomarkers](https://www.test-well.com/biomarkers) --- Medically reviewed by Youmna DiStefano, MD (Medical Reviewer, TestWell); last reviewed 2026-09-05. Review policy: https://www.test-well.com/reviewers/youmna-distefano-md Canonical page: https://www.test-well.com/biomarkers/free-t3 Machine-readable catalog: https://www.test-well.com/api/catalog.json · MCP server: https://www.test-well.com/mcp · Overview for agents: https://www.test-well.com/llms.txt Prices are cash-pay, in USD, and include physician authorization; every order adds one flat $6 lab processing fee. Educational content is not a diagnosis — discuss results with a clinician.