Thyroid profile explained: T3, T4 and TSH

TSH is often the first thyroid marker. T3 and T4 complete the picture when your clinician needs more detail.

Biotin supplements can interfere with some immunoassays — mention all medicines and vitamins at collection.

No routine fasting is required for thyroid profiles unless bundled with a lipid or glucose test.

Educational content only. Follow your endocrinologist or treating physician.