Arrange your collection
Choose your location, add the test to your care bag and select a time. If you are booking for someone else, assign the test to them in checkout.
Choose collection locationEndocrinology · Individual laboratory test
Thyroxine, Free (FT4)
Free T4 measures the proportion of thyroxine circulating independently of carrier proteins. It is frequently read alongside TSH.
Price for this test on its ownAED 135Test price AED 35
Clinical authorDr Nirupama SabhapathySpecialist Clinical Pathology
- Sample
- Serum
- Laboratory turnaround
- 24 hours
- Collection
- Dubai
- Laboratory
- Intel Lab
Understanding the test
What does the Free Thyroxine (FT4) test measure?
Also called Free Thyroid Hormone (FT4)
A free T4 result complements TSH in the assessment of thyroid symptoms, including when the two appear inconsistent with the clinical picture.
When it may be requested
Clarifying an abnormal TSH
Free T4 measures the fraction of thyroxine available outside its binding proteins.
Checking a change over time
The test can help a clinician interpret symptoms alongside the pituitary signal and treatment history.
Before your sample
Prepare for collection
SpecimenSerum
Your checklist
A recent thyroid hormone dose can affect free T4. Confirm whether the draw should precede your usual dose, and tell the team about biotin. Fasting is generally unnecessary.
A clinician takes a small sample of blood from a vein. The laboratory uses serum, the liquid separated from the blood after it clots.
Smart Report
Understanding your result
24 hoursLaboratory turnaround
Result guideThyroxine, Free (FT4)
Reading your result
The relation between free T4 and TSH can suggest where further assessment is needed. A clinician also considers recent illness and thyroid medication timing.
What can affect it
- Timing of thyroid medicines and some supplements can affect the measured result.
From sample to follow-up
Your testing journey
Laboratory testThyroxine, Free (FT4)
- Specimen
- Serum
- Turnaround
- 24 hours
Open your laboratory report
Look for Thyroxine, Free (FT4) in your report. Use the sample type and collection time when comparing it with an earlier report.
Explore Smart Report
Discuss the next step
Ask how free T4 and TSH fit together and whether recent changes in medicines or illness affect the interpretation.
Health packages
Packages that include this test
Compare the other tests in each package before choosing.
Clinical expertise
Your laboratory team
Patient questions
Before you book
What if I already take thyroid medication?
Tell the team the name of the medicine and the time of your last dose. Follow your prescriber's instructions about the timing of the blood draw.
Can biotin supplements affect a free T4 result?
High-dose biotin in some hair, nail or B-complex supplements can give a falsely abnormal free T4 result with certain testing methods. Tell the team the product, dose and time you last took it so they can advise whether to pause it or reschedule.
Why is free T4 tested together with TSH?
Free T4 carries its meaning next to TSH rather than alone. When the two move in opposite directions, the problem usually lies in the thyroid itself; when both are low, a pituitary cause comes into question. TSH is the more sensitive screen, while free T4 shows how much usable hormone is actually circulating and reacts to a dose change faster.
KEEP EXPLORING
Explore health packages.
Open a package to see exactly which tests it includes.
Thyroid Function
TSH, FT4 and FT3 from one blood sample, to check for an underactive or overactive thyroid.
- biomarkers
- 3
- Samples
- Blood
- Listed turnaround
- 24 hours
AED 199
Explore package
Executive Health Checkup
A whole-body screen of blood, urine and stool with kidney, liver, lipid, iron, diabetes and vitamin markers, plus thyroid function and a full…
- biomarkers
- 77
- Samples
- Blood + Urine + Stool
- Listed turnaround
- 48 hours
AED 429
Explore package
Menopause Profile
A targeted panel assessing hormonal, thyroid, lipid and general health markers relevant during the menopausal transition.
- biomarkers
- 59
- Samples
- Blood + Urine
- Listed turnaround
- 48 hours
AED 399
Explore package
Hair Loss Profile
A focused panel checking the iron, thyroid, hormonal and vitamin markers most commonly linked to hair loss.
- biomarkers
- 32
- Samples
- Blood
- Listed turnaround
- 48 hours
AED 449
Explore packageChoosing for a particular need?
We can help you read the options.
Your next step
Free Thyroxine (FT4) test at home.
Sources & further reading
Written by Dr Nirupama Sabhapathy, Specialist Clinical Pathology. Medically reviewed by Dr Joyce Jose, Specialist Clinical Pathology, on .
Catalogue information and AED price checked on 2 November 2026. Clinical suitability, preparation, collection arrangements and turnaround are confirmed for your selected test.