205 EGP
- Test code
- FT4
- Sample type
- Blood sample
- Fasting
- No fasting needed
- Result time
- Within 6 hours
- Home sampling
- Available
- Reference range
- 0.8 – 1.8 ng/dL
Free T4 is the free, active part of the thyroxine hormone. Low Free T4 with high TSH confirms an underactive thyroid; high Free T4 with low TSH points to an overactive one.
It is also used to follow thyroid treatment doses every few months.
Preparation before the test
- No fasting needed; it can be done any time.
- Stop biotin (B7) supplements 48 hours before; it affects the result.
This information is for awareness only and is not a substitute for medical advice — your treating doctor interprets the result for your case.
