Is my Anti-Thyroglobulin Antibodies normal?
Free blood test checker · Standard + longevity-optimal ranges
What is a normal Anti-Tg level?
Anti-thyroglobulin antibodies target thyroglobulin, the protein used by the thyroid gland to produce T3 and T4 hormones. Present in ~60% of Hashimoto's cases (vs. ~90% for anti-TPO), making it important to test alongside anti-TPO for a complete autoimmune thyroid assessment. Standard normal is 0-40 IU/mL, but functional optimal is < 2 IU/mL. Above 100 IU/mL is strongly associated with autoimmune thyroid disease. Anti-thyroglobulin is also critical for monitoring thyroid cancer recurrence — elevated levels can interfere with thyroglobulin tumor marker assays.
| Range | Values |
|---|---|
| Standard Reference | 0–40 IU/mL |
| High Risk | > 100 IU/mL |
What causes abnormal Anti-Tg levels?
Elevated anti-thyroglobulin is caused by Hashimoto's thyroiditis, Graves' disease, differentiated thyroid cancer (papillary, follicular), other autoimmune conditions (type 1 diabetes, pernicious anemia, rheumatoid arthritis), and can occur transiently after thyroid surgery or radioiodine therapy. Low-level elevations are found in ~10% of the healthy population, particularly older women.
When should you see a doctor?
See your doctor if anti-thyroglobulin is above 40 IU/mL, especially if TSH is abnormal or you have thyroid symptoms (fatigue, weight changes, neck swelling). Above 100 IU/mL strongly suggests autoimmune thyroid disease. Thyroid cancer patients with positive anti-thyroglobulin require specialized monitoring protocols.
Anti-Tg and longevity
Anti-thyroglobulin antibodies, like anti-TPO, signal autoimmune thyroid activity that may precede clinical hypothyroidism by years. The presence of both antibodies together significantly increases the risk of progression to overt hypothyroidism. From a longevity perspective, autoimmune thyroid disease is part of the broader autoimmune spectrum — having one autoimmune condition increases risk for others. Monitoring thyroid antibodies enables earlier intervention and optimization of thyroid function, which affects metabolism, cardiovascular health, cognitive function, and overall vitality.
Where to get a Anti-Tg test
Affiliate disclosure: Some links on this page are affiliate links. Otto may earn a commission at no extra cost to you. This does not affect our recommendations.
Related biomarkers
These biomarkers are often tested alongside Anti-Tg for a more complete picture.
Frequently asked questions
What is a normal anti-thyroglobulin level?
How is anti-thyroglobulin different from anti-TPO?
Why is anti-thyroglobulin tested in thyroid cancer patients?
Check all your biomarkers at once
Upload any blood test PDF and get your complete BioMap — a visual map of every biomarker in your panel. Free, instant, no account required.
Upload your labs — Get your BioMapMore biomarker checkers
Sources: Reference ranges based on AHA/ACC, ADA, and AACE clinical guidelines. Biological variation data from Ricos/Westgard database. Longevity-optimal ranges reflect targets used by preventive and functional medicine practitioners.
Last reviewed: April 2026. This tool provides general health information and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider about your specific results.