Home kit
Creatinine and eGFR Test
Creatinine with the calculated eGFR, the standard measure of how well the kidneys are filtering.
- Doctor-reviewed results
- Laboratory analysis
- 1 to 2 working days from lab receipt
- No fasting required
What’s included
2 markers measured
Creatinine
A waste product measured in the blood as the main test for kidney disease. Combined with age and sex, it is used to work out eGFR, an estimate of how much the kidneys can filter each minute. A lower eGFR can point to chronic kidney disease.
eGFR
eGFR (estimated glomerular filtration rate) is an estimate of how well your kidneys filter waste from the blood. It is calculated from the level of creatinine, a waste product, in your blood, together with your age and sex. A lower rate can be a sign of chronic kidney disease.
Overview
Creatinine with the eGFR calculated from it is how kidney function is measured in routine UK practice. It is a sensible thing to have on record if you take blood pressure tablets or anti-inflammatories, have diabetes, or simply want a baseline to compare against in a few years.
Creatinine is a waste product from muscle that the kidneys clear, so the level in blood reflects how well they are filtering. The eGFR turns that into an estimated filtration rate using your age and sex. Muscle mass matters: a heavily built person or someone who has just done a hard session can read higher without anything being wrong, and being short of fluid does the same. Kidney function is judged on the trend across repeated tests, not on a single reading.
Who this is for and who it isn’t
Who it’s for
- Adults aged 18 and over
- Anyone on blood pressure tablets or regular anti-inflammatory painkillers
- People who want a kidney baseline to compare against in a few years
Who it isn’t for
- Creatinine depends on muscle, so a heavily built person can read higher and a very slight one lower without anything being wrong with the kidneys, and a hard training session or dehydration on the day shifts it too. eGFR is an estimate for that reason, and it is judged on the trend across repeated results, not a single figure. This also misses protein in the urine, which is one of the earliest signs of kidney damage and needs a urine test. Creatine supplements raise creatinine directly.
- 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
- Taking blood pressure tablets or regular anti-inflammatory painkillers
- Diabetes or high blood pressure
- Kidney disease in a close relative
- Wanting a baseline before starting a new long-term medicine
- Following a previous eGFR that was slightly low
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.
- CreatinineIn range
- Result
- 78 µmol/L
- Range
- 45–84 / 59–104
- eGFR▼ Low
- Result
- 58 mL/min/1.73m²
- Range
- >60
| Marker | Result | Units | Range | Flag |
|---|---|---|---|---|
| Creatinine | 78 | µmol/L | 45–84 / 59–104 | In range |
| eGFR | 58 | mL/min/1.73m² | >60 | ▼ Low |
Doctor’s note (example)
eGFR is just below 60, which on a single reading does not mean kidney disease; muscle mass, hydration and a recent meal all affect it. It is repeated in three months, and a urine protein check adds to the picture.
Ranges shown as women / men. 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
Do I need to fast?
You do not need to fast, but do not eat any meat in the 12 hours before your sample, because meat can raise creatinine for a while. Drink normally and avoid a hard training session on the day, since being short of fluid or heavy exercise both push creatinine up temporarily.
Does a low eGFR mean kidney disease?
Not on one reading. eGFR drifts down naturally with age. UK guidance repeats a first result below 60 within two weeks, and kidney disease based on eGFR alone is only considered if it stays low for at least three months. The doctor's note explains where you sit.
Do creatine supplements affect it?
Yes. Creatine raises blood creatinine directly, which lowers the calculated eGFR without the kidneys doing anything differently. Tell the reviewing doctor if you take it.
Should I add urea?
Urea adds context about hydration and protein intake. The Kidney Function Test includes urea, creatinine and eGFR together for £25 less than buying urea and this test separately.
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.
People also check
See all longevity & prevention tests
Active Vitamin B12 TestActive B12 (holotranscobalamin), the fraction of vitamin B12 your cells can actually use.£40.99Includes postageView test
Advanced Thyroid Check with AntibodiesA full thyroid panel: TSH, total and free T4, free T3, and two antibodies that can point to an immune reaction against the thyroid gland.£163.00Includes clinic appointmentView test
Advanced Vitamin CheckThe widest vitamin panel here: ten direct blood measurements covering vitamins A, D and E, beta carotene, and the B vitamins including red-cell folate and active B12.£587.00Includes clinic appointmentView test