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Home › Blood tests › Markers

Cheapest Free T4 Blood Test UK

The unbound form of the thyroid's main hormone.

Add to my panel

Cheapest test that includes it£35.00Underactive Thyroid (Levothyroxine) Monitoring Blood Test at Medichecks, all-in with a home kit
Tests compared61from 11 providers, checked 29 October 2026

What it measures

Free T4 is the unbound part of thyroxine, the main hormone made by the thyroid gland. Only the unbound part is available to the body's cells. It is usually read with TSH to show how the thyroid is working.

Why people test it

Typical range

Ranges vary between labs with the method used, age and sex, and your report shows the lab's own range. One NHS trust's lab uses 10 to 20 pmol/L for adults. Source: Leeds Teaching Hospitals NHS Trust: Blood Sciences Reference Range Database v3.20.

Finger-prick or vein?

A finger-prick sample is usually fine for free T4.

Every Free T4 test, cheapest first

Cheapest first, whether the test is of Free T4 alone (marked "single-marker test") or a panel that includes it. Each price is all-in: the test and the cheapest way to have the blood taken that suits this marker, before any discount code.

Free T4 tests and their all-in prices
TestAll-inLink
Underactive Thyroid (Levothyroxine) Monitoring Blood Test
Medichecks · 2 markers · checked 26 October 2026		£35.00
with a home kit		View at Medichecks (opens in a new tab)
Thyroid Test
YorkTest · 2 markers · checked 23 October 2026		£41.00
with a home kit		View at YorkTest (opens in a new tab)
Thyroid Function Blood Test
Medichecks · 3 markers · checked 25 October 2026		£45.00
with a home kit		View at Medichecks (opens in a new tab)
Thyroid Profile Blood Test
MyHealthChecked · 2 markers · checked 28 October 2026		£45.00
with a home kit		View at MyHealthChecked (opens in a new tab)
Thyroid Function Blood Test
Goodbody Clinic · 3 markers · checked 24 October 2026		£49.00
with a home kit		View at Goodbody Clinic (opens in a new tab)
Thyroid Blood Test
Forth · 3 markers · checked 29 October 2026		£50.00
with a home kit		View at Forth (opens in a new tab)
Thyroid Function Blood Test
Vitall · 3 markers · checked 26 October 2026		£59.00
with a home kit		View at Vitall (opens in a new tab)
Thyroid Function
Bluecrest Wellness · 2 markers · checked 29 October 2026		£65.00
with a vein draw		View at Bluecrest Wellness (opens in a new tab)
Thyroid Function with Antibodies Blood Test
Medichecks · 5 markers · checked 24 October 2026		£65.00
with a home kit		View at Medichecks (opens in a new tab)
Advanced Thyroid Home Blood Test Kit
Forth · 5 markers · checked 29 October 2026		£69.00
with a home kit		View at Forth (opens in a new tab)
Menopause Check Blood Test
Medichecks · 5 markers · checked 28 October 2026		£69.00
with a home kit		View at Medichecks (opens in a new tab)
Menopause Blood Test
Goodbody Clinic · 5 markers · checked 29 October 2026		£79.00
with a home kit		View at Goodbody Clinic (opens in a new tab)
Tiredness and Fatigue Check Blood Test
Medichecks · 7 markers · checked 26 October 2026		£79.00
with a home kit		View at Medichecks (opens in a new tab)
Hair Loss Check Blood Test
Medichecks · 7 markers · checked 28 October 2026		£85.00
with a home kit		View at Medichecks (opens in a new tab)
Cardiovascular Blood Test
Numan · 11 markers · checked 24 October 2026		£88.00
with a home kit		View at Numan (opens in a new tab)
Full Check-up / Core Blood Test
Numan · 13 markers · checked 27 October 2026		£88.00
with a home kit		View at Numan (opens in a new tab)
Essential Hormone Analysis
Numan · 13 markers · checked 27 October 2026		£88.00
with a home kit		View at Numan (opens in a new tab)
Metabolic Health Blood Test
Numan · 11 markers · checked 27 October 2026		£88.00
with a home kit		View at Numan (opens in a new tab)
Female Hormone Imbalance Test
Forth · 10 markers · checked 29 October 2026		£89.00
with a home kit		View at Forth (opens in a new tab)
Male Hormone Blood Test
Forth · 11 markers · checked 29 October 2026		£89.00
with a home kit		View at Forth (opens in a new tab)
PCOS Blood Test
Goodbody Clinic · 9 markers · checked 27 October 2026		£89.00
with a home kit		View at Goodbody Clinic (opens in a new tab)
Advanced Thyroid Function Blood Test
Medichecks · 10 markers · checked 26 October 2026		£89.00
with a home kit		View at Medichecks (opens in a new tab)
Thyroid Antibody Test
LetsGetChecked · 5 markers · checked 28 October 2026		£99.00
with a home kit		View at LetsGetChecked (opens in a new tab)
Female Hormone Check Advanced Blood Test
Medichecks · 11 markers · checked 25 October 2026		£99.00
with a home kit		View at Medichecks (opens in a new tab)
Tiredness & Fatigue Blood Test
Forth · 6 markers · checked 29 October 2026		£105.00
with a home kit		View at Forth (opens in a new tab)
Thyroid Function with Antibodies Blood Test
Goodbody Clinic · 5 markers · checked 25 October 2026		£109.00
with a vein draw		View at Goodbody Clinic (opens in a new tab)
Male Hormones Clarity 14
Lola Health · 13 markers · checked 29 October 2026		£110.00
with a home kit		View at Lola Health (opens in a new tab)
Complete Cardiovascular Blood Test
Numan · 17 markers · checked 26 October 2026		£118.00
with a home kit		View at Numan (opens in a new tab)
Thyroid & Hormonal Function
Lola Health · 9 markers · checked 29 October 2026		£119.00
with a home kit		View at Lola Health (opens in a new tab)
Weight Management Blood Test
MyHealthChecked · 11 markers · checked 26 October 2026		£119.00
with a home kit		View at MyHealthChecked (opens in a new tab)
Essential Well Man Blood Test
Goodbody Clinic · 16 markers · checked 28 October 2026		£129.00
with a home kit		View at Goodbody Clinic (opens in a new tab)
Essential Well Woman Blood Test
Goodbody Clinic · 16 markers · checked 27 October 2026		£129.00
with a home kit		View at Goodbody Clinic (opens in a new tab)
Energy Profile Blood Test
MyHealthChecked · 27 markers · checked 28 October 2026		£130.00
with a home kit		View at MyHealthChecked (opens in a new tab)
Male Fertility IQ Blood Test
Medichecks · 14 markers · checked 23 October 2026		£138.20
with a vein draw		View at Medichecks (opens in a new tab)
Female Fertility Test
Forth · 9 markers · checked 29 October 2026		£144.00
with a home kit		View at Forth (opens in a new tab)
Sports Hormone Check Blood Test
Medichecks · 29 markers · checked 23 October 2026		£144.00
with a vein draw		View at Medichecks (opens in a new tab)
Well Man Screen
Better2Know · 32 markers · checked 26 October 2026		£145.00
with a vein draw		View at Better2Know (opens in a new tab)
Well Woman Screen
Better2Know · 32 markers · checked 25 October 2026		£145.00
with a vein draw		View at Better2Know (opens in a new tab)
Female Hormones Clarity 31
Lola Health · 24 markers · checked 29 October 2026		£155.00
with a vein draw		View at Lola Health (opens in a new tab)
Advanced Essential Blood Test
Medichecks · 34 markers · checked 28 October 2026		£170.00
with a vein draw		View at Medichecks (opens in a new tab)

Showing the cheapest 40 of 61. The tool above finds the cheapest for any set of markers.

Cheapest Free T4 test over time

In these presets

Providers selling it

Other thyroid markers

Prices checked daily — always confirm on the provider's site. Not medical advice.

Price data from Blood Tests - Head to Head (CC BY 4.0).

Also known as: free t4, ft4, free thyroxine, free thyroxine (ft4), free thyroxine (free t4), thyroxine (t4, free direct), free t4 (ft4), t4 free.