Home kit
Thyroid Check with T3
TSH, free T4 and free T3, measured together from one sample.
- Doctor-reviewed results
- Laboratory analysis
- 1 to 2 working days from lab receipt
- No fasting required
What’s included
3 markers measured
Free T3
Free T3 (triiodothyronine) is one of the main hormones made by the thyroid, checked alongside TSH and T4 in a thyroid function test. A low TSH with high T3 and/or T4 usually points to an overactive thyroid.
Free T4
Free thyroxine (FT4), one of the main thyroid hormones. It is read alongside TSH, the pituitary hormone that controls thyroid hormone production: a low TSH with a raised T3 or T4 usually points to an overactive thyroid. What counts as normal varies with age and laboratory method.
TSH
Thyroid-stimulating hormone, released by the pituitary gland to prompt the thyroid to make T4 and T3. Thyroid hormone levels feed back to control it, so a TSH above the normal range points to an underactive thyroid, especially when free T4 is low.
Overview
TSH, free T4 and free T3 measured together: TSH is the signal from the pituitary gland, and free T4 and free T3 are the hormones the thyroid produces. Measured together, they give a doctor a fuller picture of how your thyroid is working. It is a common choice when tiredness, weight change, feeling cold or low mood have raised the question, or when a family member has a thyroid condition.
TSH, free T4 and free T3 measured together from one home sample. A doctor reads them alongside symptoms such as tiredness, weight change, feeling cold or low mood.
Who this is for and who it isn’t
Who it’s for
- Adults aged 18 and over
- Anyone feeling cold, tired or gaining weight without a clear reason
- People monitoring a stable levothyroxine dose, using the sample timing advised by their prescriber
Who it isn’t for
- Thyroid problems are one of many possible reasons for tiredness, alongside poor sleep, stress, low iron and blood sugar problems. This panel does not include the thyroid antibodies, which the Advanced Thyroid Check with Antibodies adds. If you are already on thyroid medication, changes to it are managed by your GP or specialist, who will have their own testing schedule.
- Anyone with a new, severe or worsening symptom: contact your GP or call NHS 111. A test you buy today is not a substitute for being examined.
Common reasons people choose this test
- Tiredness that has not improved with rest
- Weight change without a change in diet
- Feeling cold when others do not, or unusually hot
- Low mood, poor concentration or brain fog
- Hair thinning, dry skin or brittle nails
- A close relative with an underactive or overactive thyroid
These are reasons people choose to test, not signs that something is wrong. A result is one part of a picture your doctor puts together with your history and an examination.
What your result looks like
Every result is shown with the unit and the reference range exactly as the laboratory reported it, with the doctor’s note underneath.
- Free T3In range
- Result
- 4.6 pmol/L
- Range
- 3.1–6.8
- Free T4▼ Low
- Result
- 10.5 pmol/L
- Range
- 12–22
- TSHIn range
- Result
- 1.8 mIU/L
- Range
- 0.27–4.2
| Marker | Result | Units | Range | Flag |
|---|---|---|---|---|
| Free T3 | 4.6 | pmol/L | 3.1–6.8 | In range |
| Free T4 | 10.5 | pmol/L | 12–22 | ▼ Low |
| TSH | 1.8 | mIU/L | 0.27–4.2 | In range |
Doctor’s note (example)
Free T4 is just below the range. With a raised TSH this pattern is consistent with an underactive thyroid, which a doctor would usually discuss treating; with a normal TSH it is repeated first.
Values above are examples. Your report shows your own results with the laboratory’s units and reference range for your age and sex, reviewed, signed and released by a GMC-registered doctor.
How it works
- Your kit arrivesPosted to your door, with instructions and what you need to send your sample back.
- You take your sampleFinger-prick sample at home, or a clinic blood draw, your choice
- The laboratory analyses itYour sample is processed for the measurements included in this test. Lab processing typically takes 1 to 2 working days from receipt of your sample.
- A doctor reviews and releases itA GMC-registered doctor reads every result and signs the report before it reaches you.
- Sample
- Home finger-prick kit
- Preparation
- No fasting required
- Who it's for
- Any sex · ages 18+
How to prepare
What we can and can’t tell you
The reference range beside each result is the laboratory’s own. A result in range is not a clean bill of health and a result outside it is not a diagnosis. Most ranges cover about 95% of healthy people, so about 1 in 20 healthy people fall just outside any one range. No test result replaces an examination or your own doctor’s judgement, and none of these panels is a cancer screening programme.
Read the full note
The reference range printed beside each of your results is the laboratory's own, and it is the range that applies to your result. We do not apply a second range of our own, and we do not tell you that a result the laboratory reported as normal is nonetheless too low or too high. If you see a claim elsewhere that your result ought to sit inside a narrower band than the one the laboratory printed, treat it with caution and ask your doctor.
Some assays cannot give an exact figure above or below a certain point, and those results are reported the way the laboratory sends them, for example as a value greater than a stated number. A result in range is not a clean bill of health, and a result outside a range is not a diagnosis: most reference ranges are set to cover about 95% of healthy people, so some healthy people fall just outside them. No blood test replaces an examination, a scan or your own doctor's judgement, and none of these panels is a screening programme for cancer.
If you have a symptom that is new, severe, or getting worse, contact your GP or NHS 111 rather than waiting for a test result. In an emergency call 999.
Frequently asked questions
Does the time of day matter?
TSH is highest during the night and lower during the day, so morning tests are the convention and repeat tests are best done at a similar time. It is worth knowing but it is not a reason to delay testing.
I take biotin. Does that matter?
It can. High-dose biotin, often found in hair and nail supplements, can make thyroid results falsely high or low. Tell us if you take it, and ask your pharmacist or GP whether to pause it before your sample.
What is the difference from the Thyroid Check?
The Thyroid Check measures TSH and free T4. This panel adds free T3. Both are available as home kits; collection options and the total price are shown when you order.
How long do results take?
The laboratory typically takes 1 to 2 working days from receiving your sample. This does not include kit delivery, sample collection or return postage. A doctor reviews your results before they are released.
Can I choose a home kit or a clinic?
Both, it is your choice at checkout. Either collect a finger-prick sample at home with the posted kit and send it back as the instructions explain, or book a clinic appointment and have a trained clinician take the sample for you.
Is a doctor involved?
Yes. Every result is reviewed by a GMC-registered doctor who signs it off and explains what it means and what to do next.
Is it confidential?
Your results are available through your secure patient portal. Our privacy policy explains how your information is handled and when it may be shared to provide your care.
What happens to my sample and results?
Your sample is analysed at a UKAS-accredited laboratory (ISO 15189). A GMC-registered doctor then reads every result and signs the report before it is released, so nothing reaches you unreviewed. There is no option to receive results without a doctor reading them first. The report arrives in your secure portal in plain English: each result with its unit and the laboratory's own reference range, and the doctor's note on what the set means read together. If a result sits outside its range the report says so and explains what usually happens next, which is most often a conversation with your own GP, who can act on it alongside your history and examination. Most reference ranges are set to cover about 95% of healthy people, so about 1 in 20 healthy people fall just outside any one of them. On a report with many results it is common for one to sit just outside its range, and a single number on its own rarely tells the whole story. If a result needs urgent attention, the reviewing doctor is alerted straight away and we contact you by phone the same working day rather than leaving it in the portal for you to find. If a specific result needs rechecking, the reviewing doctor says so in your report.
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