A free T3 test measures the level of free triiodothyronine (T3) in your blood. T3 is a hormone produced by the thyroid gland that regulates metabolism, energy levels, and other bodily functions. This test measures the level of T3 hormone in the blood that is not bound to proteins, providing a partial assessment of thyroid function. This test helps evaluate whether the thyroid is producing the right amount of T3, which is essential for regulating metabolism and energy levels.
Testing free T3 level can help you and your healthcare provider evaluate symptoms and conditions that may be related to a free T3 level. Free T3 is often evaluated in the context of other thyroid function tests such as thyroid-stimulating hormone (TSH) and free T4 to gain a full picture of your thyroid health.
Preparation: If you’re taking a supplement containing biotin (also called vitamin B7 or B8, vitamin H, or coenzyme R), commonly found in products promoting nail, skin and hair health, it is recommended that you wait at least 72 hours from your last dose before sample collection.
Free T3, or triiodothyronine, is a hormone produced by the thyroid gland that plays a crucial role in regulating metabolism, heart function and overall energy levels. This test measures the amount of free T3 in the blood, which is the active form not bound to proteins. A free T3 level helps assess thyroid function and evaluate conditions such as hyperthyroidism (too much thyroid hormone) or pituitary disorders. Elevated free T3 levels may indicate an overactive thyroid, which can lead to symptoms such as irregular heartbeat, weight loss, anxiety and fatigue.
You may want to consider testing your free T3 level if you are experiencing symptoms of hyperthyroidism such as fatigue, trouble sleeping, weight loss or mood changes. A free T3 test can help you and your healthcare provider evaluate symptoms and conditions related to T3 levels.
You may want to consider testing your free T3 level if you are experiencing symptoms of hyperthyroidism such as fatigue, trouble sleeping, weight loss or mood changes. A free T3 test can help you and your healthcare provider evaluate symptoms and conditions related to T3 levels.
Symptoms of hyperthyroidism may include1:
A free T3 blood test allows you to see how well your thyroid is producing the active hormone that drives energy, metabolism and mood, empowering you to make informed decisions for better health and well-being.
Thyroid hormones T4 and T3 play a key role in regulating your metabolism. A free triiodothyronine (T3) test may help uncover how your thyroid is impacting your cells and your metabolism.
1. Medline Plus. Triiodothyronine (T3) Tests. Accessed October 9, 2024. https://medlineplus.gov/lab-tests/triiodothyronine-t3-tests.
<p>1. Medline Plus. Triiodothyronine (T3) Tests. Accessed October 9, 2024. <a title="triiodothyronine-t3-tests" href="https://medlineplus.gov/lab-tests/triiodothyronine-t3-tests" target="_blank">https://medlineplus.gov/lab-tests/triiodothyronine-t3-tests</a>.</p>
Simply purchase this test online. A healthcare provider will review and approve your test requests; no healthcare provider visit is required.
Visit a Labcorp location near you for sample collection. Visits may be scheduled online.
View your easy-to-read results online in your Labcorp Patient™ account, including Linked Accounts. For certain results that require prompt attention, you will also be contacted by phone or mail.
Elevated free T3 levels may indicate hyperthyroidism. You may need a free T3 test if you have symptoms.1 Symptoms may include:
The normal range for free T3 levels may vary depending on the laboratory that performs the test, as well as age and sex. Your test results will include Labcorp’s reference range for the free T3 test. In general, a normal range of free T3 for healthy adults is between 2.0-4.4 pg/mL.
It is important to note that ranges will vary slightly from person to person, and your healthcare provider will consider your overall health, symptoms and test results when interpreting your levels. It is recommended to consult with a healthcare provider if you have any questions about your results.
Your testing will be performed in a CLIA-certified clinical laboratory. Labcorp provides leading-edge medical laboratory tests and services through a national network of primary clinical laboratories and specialty testing laboratories. Our labs perform regular quality assurance testing to ensure our results are accurate.
Your results will be provided to you through our secure online portal to view or print. Results are also made available through a secure portal to the independent healthcare provider who placed your test order. If you are accessing your results through your Labcorp Patient™ account, all users linked to the account will have access to all OnDemand test results. Results may also be provided to a local, state, and/or federal health authority; for example, many states require the testing laboratory and physician to report test results for certain communicable diseases, such as COVID-19, to local or state health departments.
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Visit the Labcorp OnDemand® website to browse and purchase laboratory tests and create your Labcorp Patient™ account to view your results. All Labcorp OnDemand testing requires an order from an authorized healthcare professional. For your convenience, Labcorp OnDemand has contracted with independent professional entities (collectively, Providers) to deliver healthcare provider services. Visit a Labcorp location for sample collection; or, if using an at-home collection kit, collect your sample yourself. We’ll let you know when your results are ready and can be accessed through your Labcorp Patient™ account.
