Thyroid

TPO Antibodies

The autoantibody marker for Hashimoto's — the most common thyroid disease in women.

Educational information from Her Form — reviewed for accuracy by our health specialists.
Not a substitute for personal medical advice. Optional 1:1 consults with Robyn, our consulting women's-health specialist, are available on request.

What it is

TPO antibodies attack thyroid tissue. They are the defining marker of Hashimoto's autoimmune thyroiditis, which causes most hypothyroidism in women.

Why it matters for women

TPO antibodies can rise years before TSH changes. Detecting them early opens the door to lifestyle, gut and nutrient interventions that may slow progression.

Optimal range

<9 IU/mL.

Standard lab range

Lab cut-off usually <35.

When it's high

  • Hashimoto's thyroiditis
  • Postpartum thyroiditis
  • Increased miscarriage risk

When it's low

  • Normal — no autoimmunity detected

References

References are provided for educational context only. Always interpret results with a qualified healthcare professional.

A note on interpretation. Ranges above are what our health specialists works to in healthy women. They are not a diagnosis — a single result always needs context from your symptoms, cycle phase and other markers.