T3 (Reverse) Blood Test Marylebone
From 1 October 2026 — until then book at South Kensington or St Paul's. South Kensington · St Paul's
£156
+ £50 phlebotomy fee (per visit)
+ £50 phlebotomy (per visit)
Confidential Results
Secure online portal
Fast Results
15 days"
Professional Service
Experienced phlebotomists
Wimpole Street, Marylebone (opening 1 October 2026)
Opening hours from 1 October 2026
- Monday
- 9am – 6pm
- Tuesday
- 9am – 8pm
- Wednesday
- 9am – 6pm
- Thursday
- 9am – 8pm
- Friday
- 8am – 5pm
- Saturday
- 10am – 4pm
- Sunday
- Closed
- Bond Street — about 6 minutes (Central, Jubilee & Elizabeth lines)
- Oxford Circus — about 7 minutes (Central, Bakerloo & Victoria lines)
Wimpole Street, Marylebone
Within the thyroid function range at Wimpole Street, the T3 (Reverse) is the test to consider when the question concerns thyroid hormone, triiodothyronine and thyroid function. It costs £156, and once the Marylebone clinic opens on 1 October 2026 a nurse or phlebotomist takes the venous blood sample (serum), with the laboratory typically reporting in 15 days. Medical services are for patients aged 16 and over, self-referral with no GP referral needed, and the laboratory report is delivered to your secure portal.
T3 (Reverse)’s place in thyroid function testing
- Sample
- venous blood sample (serum)
- Laboratory turnaround
- 15 days
- Appointment
- 20 minutes
- Standard price
- £156 + £50 phlebotomy per visit
What T3 (Reverse) measures
Laboratories file the T3 (Reverse) under thyroid hormone, triiodothyronine and thyroid function. The following sections set out how a thyroid function test of this kind is measured and read.
Thyroid tests measure the pituitary signal (TSH) together with the hormones the gland releases in response, free T4 and free T3, and in some panels the antibodies that target thyroid tissue. Because TSH rises when the gland is underactive and falls when it is overactive, the combination helps to show which direction, if any, the system has drifted. Antibody results add context on whether an autoimmune process may be involved.
Who considers T3 (Reverse)
- People often consider thyroid testing if they feel persistently tired, cold or low in mood without an obvious explanation.
- It is commonly requested when weight has changed noticeably despite stable eating habits.
- Palpitations, tremor, heat intolerance or anxiety that appeared over weeks rather than years can prompt a check.
- Those already taking levothyroxine or carbimazole may want an interval reading between NHS reviews.
- A family history of thyroid disease, or a recent pregnancy, is another frequent reason.
Preparing for your T3 (Reverse)
- 1No fasting is required, though many people prefer a morning appointment as TSH is a little higher early in the day.
- 2If you take levothyroxine, taking your dose after the sample rather than before gives a steadier free T4 reading; do not skip a dose without advice.
- 3Biotin supplements can interfere with some thyroid assays; pausing them for 48 hours beforehand is sensible unless prescribed.
- 4Let the nurse know if you have been acutely unwell recently, as illness can shift results temporarily.
Sample for this test: venous blood sample (serum).
Understanding your T3 (Reverse) results
A raised TSH with a low free T4 can indicate an underactive gland, while a suppressed TSH with raised T4 or T3 may point the other way; mildly abnormal TSH alongside normal hormones is usually repeated before any conclusion is drawn. Positive thyroid antibodies show an autoimmune tendency but do not on their own mean treatment is needed. The laboratory report shows where each value sits against the reference range; whether a repeat or further assessment is worth arranging is something to discuss with your GP or a clinician.
Thyroid values fluctuate with time of day, illness and medication, so a single result is interpreted alongside your symptoms and history rather than in isolation.
Related areas of testing at Wimpole Street: pituitary and growth hormones, autoimmune and immunology, wellness and biochemistry profiles, menopause and perimenopause.
Pricing
T3 (Reverse)
Individual test
Phlebotomy Fee
Blood draw by qualified phlebotomist (per visit)
Total
£206Payment is collected at the clinic. The phlebotomy fee is charged once per visit, regardless of the number of tests booked.
From booking the T3 (Reverse) to reading your result
- 1
Choose your test
Select the T3 (Reverse) and any others you want run from the same visit. Until 1 October 2026 the identical test can be booked at South Kensington or St Paul’s.
- 2
Nurse-led sample
From 1 October 2026 the venous blood sample (serum) is taken at 22 Wimpole Street, Marylebone by our nursing team, led by Precious Agbonmamwen, Registered Adult Nurse (NMC 20H1641E). Identity is checked and any preparation questions answered first.
- 3
UKAS-accredited laboratory
The sample travels to a UKAS-accredited partner laboratory, whose methods and reference ranges match those used across the NHS and private sectors.
- 4
Laboratory report to your secure portal
The laboratory report is released to your secure portal — typically from 24 hours; the laboratory quotes 15 days for this test. It shows each value against the reference range and flags anything outside it; discuss the report with your GP or a clinician.
Why test at Wimpole Street
Wimpole Street Medical & Dental opens at 22 Wimpole Street on 1 October 2026. Medical services are for patients aged 16 and over; registration with the CQC is in progress ahead of opening.
Wimpole Street, Marylebone (opening 1 October 2026)
- Bond Street — about 6 minutes (Central, Jubilee & Elizabeth lines)
- Oxford Circus — about 7 minutes (Central, Bakerloo & Victoria lines)
- Analysis is carried out by a UKAS-accredited partner laboratory, so methods and reference ranges match those used across the NHS.
- Self-referral: you choose the test and book directly — no GP referral is needed, and the laboratory report is yours to take to your GP or a clinician.
- One standard price applies to everyone — there is no members’ tier at Wimpole Street.
Other tests often considered alongside T3 (Reverse)
- Thyroid Profile 2 (Venous)Wimpole Street, Marylebone · from 1 October 2026
- Thyroid Abs (Thyroglobulin + Thyroid Peroxidase Abs) (Venous)Wimpole Street, Marylebone · from 1 October 2026
- Reverse T3Wimpole Street, Marylebone · from 1 October 2026
- Free T4 (Venous)Wimpole Street, Marylebone · from 1 October 2026
- TSH (Venous)Wimpole Street, Marylebone · from 1 October 2026
- Thyroid Profile 3 (FT3/FT4/TSH) (Venous)Wimpole Street, Marylebone · from 1 October 2026
Frequently Asked Questions
A venous blood sample (serum). A nurse or phlebotomist collects it at 22 Wimpole Street, Marylebone from 1 October 2026; the appointment allows time for identity checks and any preparation questions. The laboratory quotes 15 days for this test.
Ready to Book Your Test?
Wimpole Street opens 1 October 2026. Register your interest for the Marylebone diary, or book the same test now at South Kensington or St Paul's.
Important information about the T3 (Reverse) at Wimpole Street
- Medical services at Wimpole Street Medical & Dental are for patients aged 16 and over.
- This is a self-referral service: you choose the test and book directly — no GP referral is needed.
- Nurse-led by Precious Agbonmamwen, Registered Adult Nurse (NMC 20H1641E), who oversees sample-taking standards, infection control and the patient pathway. The nursing team does not interpret results.
- A laboratory result is not a diagnosis and this page is not a substitute for medical advice. We do not provide clinical interpretation of results — please discuss your report with your GP or a clinician, particularly if a value is flagged or you have symptoms.
- CQC registration for Wimpole Street is in progress ahead of the opening on 1 October 2026; our South Kensington and St Paul’s clinics are CQC registered.
- Your results are held on a secure portal and treated as strictly confidential, except where disclosure is required by law.
- If you are seriously unwell, call 999. For urgent advice that is not an emergency, call NHS 111.
