tTG-IgA levels: what's normal, high and low
The primary blood test for celiac disease. Looks for antibodies against tissue transglutaminase.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
The short answer
tTG-IgA is measured with a standard blood draw; no fasting is needed. A typical reference range is 0.000 – 4.00 U/mL. At TestWell it's $124.99 all-in as Celiac Disease Panel, results in 3–7 business days, drawn at Quest. An out-of-range result is a prompt to look closer, not a diagnosis.
- Units
- U/mL
- Sample
- Blood draw
- Fasting
- Not required
- Results
- 3–7 business days
- Price
- $124.99
- Labs
- Quest · BioReference in NY/NJ
tTG-IgA 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 – 4.00 U/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.
What your tTG-IgA result may mean
Strongly suggests celiac disease, especially when paired with symptoms or genetic risk. Confirmed by biopsy.
What a high tTG-IgA 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.
How do you get a tTG-IgA test?
Order online, a licensed physician reviews the requisition, and you walk into a nearby lab for the draw. tTG-IgA is available on its own or inside these panels — panels cost less per marker when you want the fuller picture.
| Option | Includes | Price |
|---|---|---|
| Celiac Disease Panel | This marker only | $124.99 |
| Gut Health Panel | 5 tests | $129.99 |
Quest vs. Labcorp for tTG-IgA: 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 | $124.99 |
| Labcorp | No | — |
| BioReference (NY & NJ) | Yes | $74.99 |
Need help choosing a location? Use the lab finder to see draw sites near your ZIP.
Related Inflammation & Autoimmune biomarkers
Markers commonly tested alongside tTG-IgA.
Frequently asked
Strongly suggests celiac disease, especially when paired with symptoms or genetic risk. Confirmed by biopsy. A single result above the reference range is a prompt to look closer with a clinician — often a repeat test and related markers — not a diagnosis on its own.
Ready to test your ttg-iga?
Order in two minutes, get physician-approved, and visit a lab the same day. Starts at $124.99.