Free T4 (Thyroxine) Test at home in Bengaluru
The free T4 test measures the active, unbound form of thyroxine, the main hormone released by the thyroid gland. It is usually tested alongside TSH to assess thyroid function.
- Price
- ₹349
- Fasting
- Not needed
- Category
- Thyroid
- Results
- During your visit
What the Free T4 Test measures
Thyroxine (T4) is the main hormone the thyroid gland produces and releases into the blood, where it is converted to the more active T3 as needed. Most T4 is bound to proteins; the free fraction measured here is the part available for the body to use.
Why it's done
- Assessing thyroid function alongside TSH
- Investigating symptoms such as fatigue, weight change or heart-rate changes
- Monitoring thyroid hormone replacement therapy, on medical advice
How to prepare
No fasting is needed — eat and drink normally. Wear something with sleeves that roll up easily, and keep a list of any medicines you take handy for your phlebotomist.
Understanding your result
Your report shows your free T4 level with the reference range. Combined with TSH, it helps your doctor tell whether an abnormal TSH reflects an underactive or overactive thyroid.
Frequently asked questions
Do I need to fast for a free T4 test?
No, this test does not require fasting.
Should I take my thyroid medication before the test?
Follow your doctor's advice — some prefer the blood draw before that day's dose. Tell the phlebotomist if you have already taken it.
Related tests
This page is general information, not medical advice, and a test result is not a diagnosis. Always discuss your results with a qualified doctor. All tests