TPO Antibodies levels: what's normal, high and low
Antibodies against thyroid peroxidase. The most common marker of autoimmune thyroid disease.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
The short answer
TPO Antibodies is measured with a standard blood draw; no fasting is needed. A typical reference range is 0.000 – 35.0 IU/mL. At TestWell it's $51.99 all-in as Thyroid Antibodies, results in 3–5 business days, drawn at Quest or Labcorp. An out-of-range result is a prompt to look closer, not a diagnosis.
- Units
- IU/mL
- Sample
- Blood draw
- Fasting
- Not required
- Results
- 3–5 business days
- Price
- $51.99
- Labs
- Quest or Labcorp · BioReference in NY/NJ
TPO Antibodies Reference Range
These are the typical adult reference ranges used by major US labs. Your report will include the specific range used by the lab that processed your sample.
| Population | Range |
|---|---|
| age 18+ | 0.000 – 35.0 IU/mL |
Reference ranges are educational. Always interpret your result with the specific range printed on your lab report and discuss anything outside the range with a clinician.
Have a result in hand? analyze it with your AI assistant using these reviewed ranges, or run it through our explainer. Tools: look up another marker's range · convert lab units
What your TPO Antibodies result may mean
Often reflects Hashimoto's (most common) or Graves' disease. Many people have elevated TPO antibodies without overt thyroid dysfunction.
What a high TPO Antibodies means: causes, symptoms, next steps ↓Educational only — not a diagnosis. Many factors can influence a single result. Discuss anything that concerns you with a healthcare provider.
What does a high TPO Antibodies mean?
TPO antibodies mark autoimmune thyroid disease — Hashimoto's thyroiditis and, in some people, Graves' disease. Around 10–15% of people (more women, more with age) test positive, and many keep a normal thyroid function for years. A positive result with a normal TSH means higher odds of developing hypothyroidism over time (roughly 2–4% per year) and matters in pregnancy planning; it is not itself a diagnosis of hypothyroidism.
Common causes of a high TPO Antibodies
- Hashimoto's thyroiditis (autoimmune hypothyroidism)
- Graves' disease
- Postpartum thyroiditis
- Other autoimmune conditions (type 1 diabetes, celiac disease, pernicious anemia) — antibodies cluster
- Normal variation — positive in a meaningful share of healthy people
Ordered from most to least common.
Symptoms that can go with it
- None from the antibodies themselves
- Hypothyroid symptoms if TSH is high; goiter
What clinicians usually check next
- TSH and Free T4 — treatment decisions rest on function, not antibody level
- Annual TSH if function is currently normal
- Closer monitoring before and during pregnancy
- Celiac and B12 screening are often considered because autoimmune conditions cluster
Follow-up tests at TestWell: TSH (Thyroid Stimulating Hormone) ($26.99), TSH + Free T4 ($27.99), Free T4 (Thyroxine) ($23.99).
My TPO antibodies are high but TSH is normal. Do I need treatment?
Not on the basis of antibodies alone. Guidelines recommend monitoring TSH (yearly, or sooner if symptoms appear) rather than treating a normal thyroid; pregnancy is the exception where thresholds differ.
Does the antibody level matter?
Higher levels modestly predict a faster progression to hypothyroidism, but the number isn't tracked for treatment — TSH is.
Educational only — not a diagnosis. A single result outside the range is a prompt to look closer with a clinician.
How do you get a TPO Antibodies test?
Order online, a licensed physician reviews the requisition, and you walk into a nearby lab for the draw. TPO Antibodies is available on its own or inside these panels — panels cost less per marker when you want the fuller picture.
| Option | Includes | Price |
|---|---|---|
| Thyroid Antibodies | This marker only | $51.99 |
| Hashimoto's Thyroid Panel | 3 tests | $97.99 |
| Advanced Thyroid Panel | 7 tests | $129.99 |
Quest vs. Labcorp for TPO Antibodies: which lab should you pick?
Both are CLIA-certified national labs and the result is clinically equivalent, so pick whichever location is closer. Your report will print that lab's own reference range, which can differ slightly from the table above.
| Lab | Available | Price |
|---|---|---|
| Quest Diagnostics | Yes | $51.99 |
| Labcorp | Yes | $51.99 |
| BioReference (NY & NJ) | Yes | $51.99 |
Need help choosing a location? Use the lab finder to see draw sites near your ZIP.
Related Thyroid biomarkers
Markers commonly tested alongside TPO Antibodies.
Frequently asked
What does a high TPO Antibodies mean?
TPO antibodies mark autoimmune thyroid disease — Hashimoto's thyroiditis and, in some people, Graves' disease. Around 10–15% of people (more women, more with age) test positive, and many keep a normal thyroid function for years. A positive result with a normal TSH means higher odds of developing hypothyroidism over time (roughly 2–4% per year) and matters in pregnancy planning; it is not itself a diagnosis of hypothyroidism.
My TPO antibodies are high but TSH is normal. Do I need treatment?
Not on the basis of antibodies alone. Guidelines recommend monitoring TSH (yearly, or sooner if symptoms appear) rather than treating a normal thyroid; pregnancy is the exception where thresholds differ.
Does the antibody level matter?
Higher levels modestly predict a faster progression to hypothyroidism, but the number isn't tracked for treatment — TSH is.
Do I need a doctor's order to test my tpo antibodies?
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 TPO Antibodies results?
Most TPO Antibodies 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 TPO Antibodies test cost?
Our Thyroid Antibodies starts at $51.99. 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 TPO Antibodies test?
Fasting is not required for the TPO Antibodies test. You can have your blood drawn any time of day.
Which lab will process my TPO Antibodies 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.
Ready to test your tpo antibodies?
Order in two minutes, get physician-approved, and visit a lab the same day. Starts at $51.99.