A patient seated in the chair before a blood draw
In person

Thyroid Panel

TSH, free T4, free T3, and TPO antibodies, from one blood draw.

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  • 2,000+ lab locations. Find one near you
  • Nothing due at the lab. FSA / HSA accepted
  • Ordered by a licensed clinician

At a glance

Collection
Blood draw
A standard blood draw at the lab.
Preparation
None
No fasting. If you have had fluorescein angiography, wait 3 days.
Results
1 to 3 days
Typical turnaround after your visit.
Where
2,000+ lab locations
Nationwide, with nothing due at the lab.

About this test

For a fuller first look than TSH alone, this panel measures TSH, the pituitary’s signal to your thyroid, plus free T4 and free T3, the thyroid hormones available to your cells, and TPO antibodies, which are linked with autoimmune thyroid conditions. No fasting is needed.

For adults 18 and older. Test availability varies by lab location.

Who should take this test?

For adults with thyroid symptoms, a family history of thyroid disease, or an out-of-range TSH who want a fuller first look at thyroid function. Commonly related symptoms include:

Body

  • Tiredness
  • Feeling too cold or too hot

Weight

  • Unexplained weight change

Hair

  • Hair thinning

Skin

  • Dry skin

Mood

  • Low mood
  • Anxiety or irritability

Heart

  • Racing heartbeat

Ask about this test

Not sure this is the right test?

AI-generated. For information only, not medical advice. Call 911 for an emergency.

What does this test measure?

Read together, these results show how your thyroid is being signaled, how much hormone it is making, and whether an antibody linked with autoimmune thyroid disease is present.

Thyroid

Thyroid-stimulating hormone (TSH)
TSH is made by the pituitary gland at the base of your brain and tells your thyroid how much hormone to make. It usually moves in the opposite direction from thyroid hormone: TSH tends to rise when the thyroid is underactive and fall when it is overactive. It is the usual first thyroid check.
Why it’s measured: Shows how strongly your pituitary gland is signaling your thyroid to work.
Free thyroxine (free T4)
Thyroxine (T4) is the main hormone your thyroid makes. Most of it travels bound to proteins in the blood; free T4 is the small unbound portion available to your tissues. It is read with TSH to help show whether the thyroid is making too little or too much hormone.
Why it’s measured: The unbound portion of the main thyroid hormone, read with TSH.
Free triiodothyronine (free T3)
T3 is a thyroid hormone made by the thyroid and from T4 in other tissues. Free T3 is the small portion that is not bound to proteins. It is mainly used, together with TSH and free T4, when an overactive thyroid is a question, and it can shift during illness.
Why it’s measured: Adds detail mainly when an overactive thyroid is a question.
Thyroid peroxidase (TPO) antibodies
TPO is an enzyme your thyroid uses to make hormone. TPO antibodies are made when the immune system targets the thyroid. They are often found in autoimmune thyroid conditions, but some people have them without thyroid problems, so a positive result is read with TSH and thyroid hormones.
Why it’s measured: Antibodies often found in autoimmune thyroid conditions, read with TSH and thyroid hormones.

How it works

  1. Step 1

    Order online

    Check out here. A licensed clinician in your state reviews your order and sends it to the lab.

  2. Step 2

    Visit a lab

    Bring a photo ID to any of 2,000+ lab locations. No fasting. If you have had fluorescein angiography, wait 3 days. Nothing is due at the lab.

  3. Step 3

    Get your results

    Results post to your account, usually in 1 to 3 days, each number next to the lab’s reference range.

Find a lab near you

Choose from 2,000+ lab locations nationwide. Your order works at any of them.

What your results tell you

TSH, free T4, and free T3 are reported as values with units, and TPO antibodies as a level, each compared with the lab’s reference range.

  • Each marker next to the lab’s reference range
  • Explained in plain language
  • A licensed clinician reviews your order and, if appropriate, orders the test.
  • A lab report you can download and share

Thyroid results are read together and with your symptoms. Only a healthcare provider can diagnose a thyroid condition or advise on care.

Which thyroid test fits?

Three thyroid options, from one marker to both antibodies.

Thyroid Panel

Thyroid hormones plus TPO antibodies.

Hormones
TSH, free T4, and free T3
Antibodies
TPO
Often chosen for
A fuller first look than TSH alone

Clinical-grade testing, from the comfort of home.

From the lab to your report, every step of our process meets the gold standard in medical testing.

  • CLIA-certified labs

    Every lab we partner with is certified under the Clinical Laboratory Improvement Amendments, meeting both state and federal standards with regular independent inspections.

  • We protect your health data

    We protect your health data with encryption and do not sell it. Some results must be reported to public health authorities by law. See our Privacy Notice.

  • Rigorous quality assurance

    All partner labs run regular internal quality checks, participate in proficiency testing, and comply with federal and state lab regulations.

  • Clinician-reviewed reports

    Results are reviewed by an independent, licensed clinician.

Questions

Common questions.

Anything else, our care team answers by phone, text, or email.

TSH is the pituitary’s signal telling the thyroid to work. Free T4 and free T3 are the thyroid hormones themselves, in the form available to your cells. Reading them together helps show whether a change starts in the thyroid or elsewhere. Free T3 is mainly used when an overactive thyroid is a question.

TPO antibodies target an enzyme the thyroid uses to make its hormones. They are linked with autoimmune thyroid conditions such as Hashimoto’s thyroiditis and Graves’ disease, and they can be present while hormone levels are still in range. A provider reads them with your other results and symptoms.

Yes. Thyroid hormone medicine changes these results, which is one way providers follow people who take it. Fluorescein dye used in some eye exams can also affect results, so the prep asks you to wait 3 days after fluorescein angiography. Tell your healthcare provider what you take.

Don’t stop or change any medicine or supplement without talking with your healthcare provider.

These blood tests show thyroid function and one antibody, not the thyroid’s structure, so they do not show nodules or explain a lump in the neck. Tiredness and weight change also have many causes outside the thyroid. A healthcare provider decides whether other tests are needed.

Lab tests are informational and don’t diagnose conditions on their own. Available to adults 18 and older; test availability varies by lab location. A licensed clinician reviews your order and, if appropriate, orders the test. All testing is performed at CLIA-certified laboratories. Not for emergencies: if you think you may be having a medical emergency, call 911.