← Royal Fitness Club Educational information only — not a substitute for medical advice. Read disclaimer ·
First-line thyroid test — high means underactive in most cases.
Updated: 12 August 2026
Do not diagnose based on one lab value. Ranges vary by lab, method, age, pregnancy and medicines — always interpret trends with your doctor.
Pituitary signal to the thyroid; inverse of thyroid output.
Typically 0.4–4.5 mIU/L (lab-specific; pregnancy targets tighter).
No — test first, then take your tablet, for consistent interpretation.
This website provides general educational information and is not a substitute for professional medical diagnosis, treatment or emergency care. Always consult a qualified healthcare professional.