Free t3

This is an important test used to diagnose thyroid problems.

Finger-prick blood
1 tests included
2 days turnaround



About Free t3

What is free T3?

Triiodothyronine (T3) is a hormone produced by the thyroid gland, it is the more powerful of the two main thyroid hormones (with T4 being the other), which regulate metabolism throughout the body. The vast majority of T3 in the body is bound to other proteins, with the remaining unbound T3 called free T3. Measuring free T3 gives an indication of thyroid function. Abnormal levels of free T3 can indicate thyroid problems such as hyperthyroidism or hypothyroidism.

Why take the test?

This test measures the level of free T3 in the blood. It is typically used to diagnose thyroid problems.


What's tested


How it works



Purchase your Kit

Just order a test online and get your kit delivered right to your door unless you are ordering a COVID-19 Fit to Fly test where you will be given appointment options to attend our clinics across the United Kingdom for a nose and throat swab PCR test at the checkout stage.



Take your test and post

Follow our simple instructions to take your sample and post back the enclosed prepaid envelope to our accredited lab for processing. We also offer home or workplace visits by a qualified nurse. For COVID-19 Fit to Fly tests you must attend one of our partner clinics for our trained collection officers to take your sample. You will then have the results emailed to you.



Get results directly to your dashboard

You will receive an email notification from our medical team when your results are available on your secure personalised health dashboard.