Free T4 test at home in Dubai
Free T4 is the main hormone your thyroid makes, measured in the unbound form your body can use. It is the clearest single read of thyroid output.
What the test measures
Free T4 (FT4). Thyroxine that is not bound to carrier proteins in the blood. Only this free fraction can enter cells, where it is converted into the more active T3.
Who should test
More than 99% of T4 in the blood is attached to carrier proteins and is not available to tissues. The amount of those proteins changes with pregnancy, the contraceptive pill and liver health, which can make a total T4 result misleading. Free T4 measures only the unbound hormone, so it tracks what the thyroid is actually supplying. The full thyroid panel, TSH, FT4 and FT3, is covered on the thyroid test page. This page goes deeper on FT4 itself.
TSH from the pituitary and FT4 from the thyroid work as a pair. When FT4 falls, TSH normally rises to push the gland harder, and when FT4 is high, TSH drops. Reading FT4 against TSH shows whether the gland, the signal or both are out of step. Low FT4 is linked with tiredness, feeling cold, weight gain and slowed thinking. High FT4 is linked with a fast heartbeat, shakiness, anxiety and weight loss.
- Tiredness, feeling cold or slowed thinking
- A fast or pounding heartbeat, shakiness or heat intolerance
- Unexplained weight change
- A past TSH result outside the range
- A family history of thyroid problems
How to prepare
- Stop biotin supplements, including hair and nail formulas, for at least two days before the draw.
- If you take thyroid medication, ask your own doctor whether to take it before or after the draw, and keep the timing the same for future tests.
- Follow the fasting instructions for the full screen and tell your consultant if you are pregnant.
Reading your results
Units and ranges
UAE labs report free T4 in pmol/L. Many adult ranges sit roughly between 12 and 22 pmol/L, but ranges vary by lab and change in pregnancy, so read your result against your own report.
If it comes back low
A low FT4 with a high TSH is the common pattern of an underactive thyroid. A low FT4 with a low or normal TSH is less common and can point to the pituitary, which needs follow-up with your own doctor.
If it comes back high
A high FT4 with a low TSH is commonly linked with an overactive thyroid. Biotin, recent illness and the timing of thyroid medication can also push FT4 up, so results are read in context.
Reference ranges differ between labs, and a single result is a snapshot. Your consultant reads every value against your history and the rest of the screen, not in isolation.
How the home test works
This test is part of Baseline’s full blood screen: 122 parameters across ten systems from one draw, for AED 850, with results in 48 hours. It is not sold as a single test, because the result means more next to everything else.
- Nurse comes to you. A licensed phlebotomist visits your home or office, 7 days a week, anywhere in the UAE.
- Accredited lab. Samples are processed by a CAP-accredited laboratory (College of American Pathologists), also accredited to ISO 15189, against clinical reference ranges.
- Reviewed with you. Results land in your account in Baseline format, and your consultant walks you through them on video, never a PDF dumped in your inbox.
Ranges are the lab’s own. Your consultant goes through what they mean with you.
Your results arrive in the Baseline app, every marker against the lab’s own range, checked by your consultant before you see them. The values above are an example.
Questions
- What is the difference between free T4 and total T4?
- Total T4 counts all the hormone, most of which is bound to proteins and inactive. Free T4 counts only the unbound portion that tissues can use, so it is less affected by pregnancy, the pill and protein levels.
- Can my FT4 be normal if my TSH is abnormal?
- Yes. A raised TSH with a normal FT4 is often called subclinical and is usually rechecked. It shows the pituitary is working harder to keep FT4 in range.
- What is a normal free T4 level?
- Many labs use a range of roughly 12-22 pmol/L for adults, but it varies by lab and method. Always compare your result with the range printed on your report.
- Can I book a free T4 test on its own?
- No. Free T4 is part of the thyroid panel in the Hormone Profile of the full home screen, measured from the same single draw.
Related tests
This page is general information, not a diagnosis. If you feel unwell, or your symptoms are new or getting worse, speak to a doctor.
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