Free T4 (Thyroid Hormone)
$39
Plus a $12 blood draw fee, charged once per order. Free when your order includes a bundle.
- Sample
- Blood draw
- Preparation
- No fasting needed.
- Results in
- 1-3 business days after your sample reaches the lab
Tests are ordered by an independent licensed physician. This service does not replace care from your own doctor. Talk with a healthcare professional about your results.
Free T4 is the unbound, active form of thyroxine, the main hormone your thyroid makes. Looking at it alongside TSH gives a fuller picture of how the thyroid is working.
People order it after an abnormal TSH, or together with TSH when they have symptoms such as fatigue, weight changes or feeling too hot or cold.
Before your visit: no fasting is needed. If you take biotin supplements, ask your doctor whether to pause them first.