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Keeping Tabs on Your Thyroid Health With a Thyroid Panel

If you’ve been concerned that your symptoms — such as fatigue, weight gain, or hair loss — are coming from a thyroid problem, running a thyroid panel is one of the first steps to take to learn more.

A thyroid panel is simply a collection of thyroid blood tests. Leaving a thyroid imbalance uncorrected can have health consequences, and a thyroid panel is the primary tool you can use to guide your diagnosis and treatment.

There are a few different schools of thought about thyroid panels. Some doctors will only look at your thyroid stimulating hormone (TSH), while others will run a complete and complex thyroid panel to monitor different markers. But which approach is best? 

In this article, we’ll cover what a thyroid panel is and which markers are most important to monitor. We’ll also discuss when you would want to run a thyroid panel, what it tells you, and what to do with your thyroid panel results.

Thyroid panel: Blood sample vial on top of a thyroid hormone checklist

What Is a Thyroid Panel (Blood Test)?

A thyroid panel is a collection of blood tests that measure your thyroid gland function. Your doctor may order a thyroid panel if they suspect a problem with your thyroid or they want to help monitor your thyroid medication.

Many doctors screen for thyroid disorders with specific blood tests like TSH [1] or TSH plus free T4. A full thyroid panel is more detailed than these specific tests.

A comprehensive thyroid panel usually includes the following markers:

Lab MarkerPurposeReference Range
TSH (Thyroid-stimulating hormone)Tells the thyroid gland to produce T4 thyroid hormone0.45−4.5 IU/mL
Free T4Thyroid hormone produced in the thyroid gland0.82−1.77 ng/dL
Free T3Thyroid hormone produced in disparate body tissues2.0−4.4 pg/mL
TPO (thyroid peroxidase) antibodiesAntibody to thyroid gland< 35 IU/mL
TG (thyroglobulin) antibodiesAntibody to thyroid gland< 0.9 IU/mL

Some thyroid panels include additional tests, but despite what many claim, most of them have limited use unless you have a very rare, complicated thyroid condition or you’re an endocrinologist. These tests include Total T3, Total T4, T3 Uptake, Free T4 Index (FTI), and thyroid-binding globulin (TBG).

Why Run a Thyroid Panel?

If you’re experiencing common thyroid symptoms such as weight gain or weight loss, hair loss, heart rate changes, or a goiter (a swollen thyroid gland), a thyroid panel can provide information to help guide treatment. This makes a thyroid panel a useful diagnostic tool.

A thyroid panel can also monitor your response to your thyroid treatment or adjust your thyroid medication.

Some practitioners recommend complex approaches to thyroid health monitoring and suggest you always do a full thyroid panel. This approach may be more intensive than what’s needed for most thyroid patients. 

Let’s have a look at the diagnostic information provided in a thyroid panel. Then, we’ll discuss a simple and rational approach to thyroid testing.

What Does a Thyroid Panel Tell You?

Different combinations of TSH and T4 indicate different types of thyroid conditions. Let’s consider what we can learn from these two initial screening tests as well as from antibodies, free T3, and reverse T3.

Meaning of thyroid panel tests infographic by Dr. Ruscio


Hypothyroidism means you have an underactive thyroid gland. Hypothyroidism is diagnosed when you have high TSH levels and low free T4 levels. 

Hypothyroidism is the most common thyroid condition, and it’s much more common in women than in men. It often co-occurs with autoimmune diseases, including celiac disease and type 1 diabetes [2].


Hyperthyroidism means you have an overactive thyroid gland, and it’s much less common than hypothyroidism. Hyperthyroidism is diagnosed when you have low TSH levels paired with a high free T4 level.  

It’s important to know that supplementing with biotin (vitamin B7) before thyroid blood tests can lead to a falsely high free T4 and Total T3 result, which can lead to an incorrect diagnosis of hyperthyroidism [3]. Stop taking B-complex or biotin supplements 2-3 days before your thyroid tests to protect against this false positive.

Subclinical Hypothyroid

Subclinical hypothyroidism is diagnosed when your TSH levels are high, but your free T4 levels are normal. In a majority of these cases, your thyroid will return to normal (euthyroid) on its own and does not require treatment [4]. 

Patients with a subclinical hypothyroid may be prescribed thyroid medication unnecessarily. Research shows that thyroid medication is commonly overprescribed. A study on thyroid medication found that 60% of 291 participants who paused their thyroid medication for 6-8 weeks saw their thyroid labs return to normal with no further treatment or intervention [5].

If your thyroid lab values are askew, try improving your gut health first (more on this below).

Central Hypothyroid 

Central hypothyroidism is a very rare thyroid condition caused by a congenital defect in the thyroid gland or a problem with the pituitary gland. In central hypothyroidism, your TSH levels are in the normal range, but your free T4 levels are low.

Autoimmune Thyroid Disease 

Hypothyroid and hyperthyroid conditions may be caused by autoimmune attacks on your thyroid gland. To diagnose autoimmune thyroid disease, your thyroid panel may test for the following thyroid antibodies:

  • TPO (thyroid peroxidase antibodies) 
  • TG (thyroglobulin antibodies)
  • TRab (thyrotropin receptor antibodies)

Elevated TPO antibodies and changes seen on a thyroid ultrasound indicate you may have Hashimoto’s thyroiditis, which can cause hypothyroidism [6]. Elevated TRab antibodies indicate you may have Graves’ disease, and you are at risk for hyperthyroidism [7].

T3 and Reverse T3 Levels

T3 test results, including free T3 (triiodothyronine) and reverse T3, should be interpreted with care by your healthcare provider.

When thyroid panel test results show low free T3 (possibly combined with high reverse T3), they may prescribe combination T4/T3 medication.

This approach fails to recognize that low T3 is usually an indicator of poor nutrition, chronic inflammation, and/or chronic illness [8]. A better approach is to treat the cause of low T3.

We’ve noticed in the clinic that low T3 levels often rebound when gut health is addressed, and research supports this approach [9, 10, 11]. For most patients, T3 medication is not required. 

What to Do With Your Thyroid Panel Test Results

In many cases, your out-of-balance thyroid panel results don’t require any action. A significant number of subclinical hypothyroidism cases or elevated thyroid antibodies return to normal on their own without treatment [12].

But even if your thyroid panel reveals you have a thyroid disorder, there’s no reason to despair. Thyroid conditions can and do respond well to treatment.

3-step approach to thyroid treatment infographic by Dr. Ruscio

At a very high level, treating thyroid disease involves a three-step approach:

  1. Take standard thyroid medication to bring thyroid hormone levels up to a normal range.
  2. Use gut-healing therapies to resolve symptoms.
  3. Retest thyroid hormone levels and adjust medications as needed.

Let’s further discuss how you can use this approach to improve your thyroid function.

1. Adjust Your Thyroid Hormone Levels With Standard Thyroid Medication

If your thyroid panel reveals that you have a thyroid condition, it’s important to take thyroid medication as prescribed by your doctor. At this point in your treatment process, it’s best to avoid alternative thyroid medications such as combination T4/T3. Standard thyroid medication works well for most patients, while our research shows that T4/T3 combination medication may only benefit about 10% of patients [13].

If your lab tests are on the margins, focus on gut health first, and reassess whether you need thyroid medication at all. Research suggests that thyroid medication is often overprescribed for marginal thyroid hormone levels or subclinical hypothyroidism [5]. 

If you’d like to learn more, this article goes into more detail about thyroid medication…

2. Support Gut Health to Improve Thyroid Function

Thyroid-like symptoms or a poor response to thyroid medication may be due to an imbalance in your gut. Gut imbalances like IBS [14, 15], small intestinal bacterial overgrowth (SIBO) [16, 17], and celiac disease [18, 19] can cause thyroid symptoms like fatigue and brain fog. This suggests the root cause of thyroid symptoms may actually be your gut. Even more interesting is that gut health improvements have been shown to benefit thyroid hormone levels and thyroid antibodies [20, 21, 22, 23, 24].

Three key steps to begin supporting your gut health include:

  1. Follow an anti-inflammatory diet, such as the paleo diet.
  2. Take quality probiotic supplements to restore balance to your gut ecosystem.
  3. Reduce stress and prioritize good sleep.

For a more comprehensive discussion of how to optimize your gut health, check out my book, Healthy Gut, Healthy You.

3. Monitor Thyroid Levels and Optimize Thyroid Medication

Feeling well with a thyroid condition is easiest when your medication dose is right and is being well absorbed. A simplified thyroid panel including TSH, free T4, and antibodies that were elevated are usually sufficient to monitor your response to thyroid medication or treatment.

Once you improve your gut health, your gut may absorb thyroid medication better. At this point, you may need to adjust your thyroid medication. 

The Bottom Line

A thyroid panel including TSH, free T4, TPO, and TG antibodies is largely enough to diagnose most thyroid conditions. Managing your thyroid medication can usually be done just with TSH, free T4, and tests. These tests can help you assess how your body is responding to thyroid replacement therapy and your level of autoimmunity.

You shouldn’t feel defeated by a thyroid diagnosis. Thyroid conditions have been shown to improve with particular diet changes, attending to your gut health, and a few particular supplements. By using a thyroid panel, you can keep good tabs on your progress and find your optimal path to thyroid health.

➕ References
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  13. FFMR December 2020
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