What it measures
Antibodies the immune system makes against thyroglobulin, a protein the thyroid uses to make its hormones. They are found in autoimmune thyroid conditions and in some people whose thyroid works normally.
Why people test it
- Checked alongside TPO antibodies when looking for an autoimmune cause of a thyroid problem.
- Measured with thyroglobulin in follow-up after thyroid cancer, as the antibodies can upset that result.
- Checked by people with thyroid symptoms or a family history of thyroid conditions.
Typical range
Ranges vary by lab, method, age and sex, and your report shows the lab's own range. Labs use different methods and cut-offs, so results from two labs may not match.
Finger-prick or vein?
A finger-prick sample is usually fine for thyroglobulin antibodies, and many providers also offer a vein draw.
High-dose biotin, found in some hair and nail supplements, can upset some lab methods used for thyroid tests.