Clinic test
Thyroid Function Test
A five-marker thyroid panel — TSH, free T4, free T3 and the two thyroid antibodies — to show whether your thyroid is under- or over-active and whether an autoimmune process is behind it.
Everything you need to know about Thyroid Function Test
Your thyroid sets the pace for your metabolism, so when it slows down or speeds up the effects show up everywhere: weight, energy, mood, sleep, temperature, heart rate, hair and skin. The symptoms overlap with ordinary tiredness and stress, which is why a blood test is the only way to know.
This panel measures Thyroid Stimulating Hormone (the pituitary’s signal to the thyroid), the active hormones free T4 and free T3, and antibodies against thyroid peroxidase (anti-TPO) and thyroglobulin (anti-TG). The antibodies matter because autoimmune thyroid disease — Hashimoto’s or Graves’ — is the most common cause of a thyroid that has stopped behaving, and knowing early changes how closely you are monitored.
What's included
5 markers in this test
Worth considering if
- Persistent tiredness, weight change, feeling unusually cold or hot
- Low mood, anxiety, brain fog or poor sleep without an obvious cause
- A family history of thyroid disease or another autoimmune condition
- Monitoring an existing thyroid condition between GP checks
Your visit
Book online
Add this test — and any others — to your booking, pick a time at the clinic and pay online. No fasting. If you take levothyroxine, tell us — we may suggest a morning slot before your dose.
Your visit
About 15 minutes at 44 Crawford Street, Marylebone. Our clinical team takes your sample (blood sample) and answers any questions.
Results explained
The laboratory analyses your sample and your results are released to your secure account with a written explanation from our clinical team — and a call where something needs talking through.
Thyroid Function Test — FAQs
Why test antibodies as well as hormones?
Do I need to fast?
What if my results are outside the range?
Can supplements affect the result?
Where is the test done?
How long does the appointment take?
Can I book several tests at once?
How do I pay, and can I cancel?
How do I get my results?
Often booked together
Add several tests to one booking — they are all taken in the same visit.





