FT3Free triiodothyronine (FT3)
What it shows
The active hormone tissues make from thyroxine; usually ordered with TSH and FT4.
Your doctor reads the result: the laboratory does not diagnose or prescribe. The result sheet gives the reference range beside each value.
Sample
- Short code
- FT3
- What is taken
- Blood from a vein
- Container
- Yellow-top gel serum tube
- Turnaround
- 1 working days for samples taken by 12:00; result at 18:00
- At home
- Yes, a nurse comes to your home
Preparation
- At least 4 hours after a light meal
- The sample is taken before 10:00
- Take your thyroid pill that morning after the blood test.
- No biotin (B7) or vitamin mixes with it for 2 days.
- No hard exercise the day before.
Reference ranges
| For | Range |
|---|---|
| Everyone | 3.1–6.8 pmol/L |
These ranges are for Damla’s analysers and methods; another laboratory’s ranges may differ slightly.
This test is part of these check-ups
From the same section
- TSHThyroid-stimulating hormone (TSH)₼20
- FT4Free thyroxine (FT4)₼20
- Anti-TPOThyroid peroxidase antibodies (anti-TPO)₼26
- FSHFollicle-stimulating hormone (FSH)₼22
- LHLuteinising hormone (LH)₼22