ClarilabThyroid
Free T4 test
Also called FT4, free thyroxine
The active, unbound form of the main thyroid hormone.
- Typical range
- About 0.8–1.8 ng/dL.
- Usual recheck
- About 2 months when out of range
Why it's done
Done with TSH to confirm a thyroid problem.
What a high result can mean
Overactive thyroid.
What a low result can mean
Underactive thyroid.
Got a report with Free T4?
Upload the PDF to Clarilab: it reads the values in your browser, flags anything out of range and tracks your results over time.