Who it is for
Is this CRP test right for you?
C-reactive protein (CRP) is made by the liver and rises quickly when the body fights an infection or an inflammation. Doctors measure it to see whether an infection or inflammation is under way, and how strong it is. A CRP test you do at home gives you that first answer in five minutes. People use it when they have:
- Fever
- Headache
- Weakness or feeling run down
- The symptoms of an acute infection, and the question whether to see a doctor
Why it is useful to know. The higher the CRP, the stronger the infection or inflammation. The level helps a doctor decide what to do next.
- A cold that drags onIs the body still fighting an infection?
- Someone at home has a feverA first answer while the doctor’s office is closed
- Before the weekendDecide today whether it can wait until Monday
- Recurring infectionsFollow how your body responds
What it measures
What this CRP test tells you, and what it does not
It tells you
- Which of four ranges your CRP is in: below 8, 8 to 40, 40 to 100, or above 100 mg/L
- Below 8 mg/L: no infection or inflammation. 8 to 40: slightly raised. 40 to 100: raised. Above 100: strongly raised
- From a fingertip blood sample, in five minutes, at home
It does not tell you
- Which infection you have, or where it is. CRP is a non-specific marker
- The exact CRP number. It places you in one of four ranges
- Whether you need an antibiotic. That decision is your doctor’s
- Anything reliable if you take statins or fibrates (they lower CRP) or oral hormone therapy for the menopause (it raises CRP)
Contents
What is in the box
- 1 × test device in a sealed foil pouch
- 1 × dropper bottle of diluent 3 mL
- 2 × plastic capillary pipettes one is a spare
- 2 × sterile lancets one is a spare
- 1 × alcohol pad
- 1 × instructions for use in seven languages
- 1 × desiccant bag discard it, do not use it
Everything you need is in the box except a timer. Keep the foil pouch sealed until you test.
How it works
Five steps, about ten minutes
01
Prepare the lancet
Very important: do not touch the trigger. Twist the grey protective cap off, never pull it. Keep turning until it comes away.
02
Take a blood sample from your fingertip
Very important: use the pipette correctly — lightly touch the drop of blood with the pipette’s tip, not the skin, do not squeeze the bulb, fill to the line.
03
Empty the blood into the diluent vial and shake well
Very important: in this test the blood goes into the vial, not onto the test device. Press the bulb 2–3 times to rinse the pipette in the diluent, screw the cap back on and shake well.
04
Add exactly 4 drops to the test device
Snap off the tip of the vial cap, hold the vial upright, and add exactly four drops to the sample well, 2–3 seconds apart.
05
Read your result after 5 minutes
Not after 10. Set a timer.
Instructions for useWatch the video demonstration
On the clock: the five minutes, step by step
- Steps 1–2: lancet, then blood
Draw a drop and fill the pipette to the line.
- Step 3: into the vial, shake
Empty the pipette into the diluent, rinse it 2–3 times, cap on, shake well.
- Step 4: four drops
Snap off the tip. Exactly four drops into the sample well, 2–3 seconds apart.
- Step 5: read
Compare the lines at numbers 1 and 2, in good light.
- Stop
Do not interpret the result after 10 minutes.
Your result
How to read your CRP test result
The result must be interpreted depending on the colour intensity of the 3 lines that could appear in the device’s interpretation window. Which line appears, and which is stronger, tells you the range. Here the strength of the colour matters.
Under 8 mg/L normal
A line at number 2, none at number 1. No infection or inflammation.
8 – 40 mg/L slightly raised
Lines at numbers 1 and 2; the line at number 2 is the stronger. A viral infection may be under way. You should see your doctor.
40 – 100 mg/L raised
Lines at numbers 1 and 2 of similar strength. A viral or bacterial infection is under way. You must see your doctor.
Over 100 mg/L strongly raised
The line at number 1 is the stronger; the line at number 2 may have disappeared. A severe bacterial infection is developing. See your doctor urgently.
Invalid repeat
No C line. The result cannot be read; repeat with a new test.
Read at 5 minutes; do not interpret the result after 10. If you are unsure which line is stronger, you can contact us. The pictures are for illustration purposes; the actual lines may differ in intensity.
Next step
What to do with your result
If your CRP is 8 mg/L or above
See your doctor and show the result — as soon as possible if it is in the 40 to 100 range, urgently if it is above 100. An antibiotic may be needed, and only a doctor can decide that.
If your CRP is below 8 mg/L
There is no sign of a bacterial or viral infection under way. If the symptoms persist, see your doctor all the same.
The technology
What happens inside the test device
All of it happens on a paper strip inside the test device, in five minutes.
- The sample moves
The diluted blood travels along the strip by capillary action. No pump, no power.
- Antibodies meet CRP
The strip carries anti-CRP antibodies and CRP antigen. The CRP in your blood reacts with them as it passes.
- Lines 1 and 2
The more CRP there is, the more the colour shifts from line 2 to line 1. That is why the strength of each line matters when you read the result.
- The C line
The excess reagent is caught at C whatever the sample holds. The C line only means that the test was performed well. No C line, no result.
This test has been used by professionals in hospitals and laboratories for more than 10 years. It places the result in one of four ranges, set against the WHO reference.
Quality
Made in France, checked batch by batch
30+
years of diagnostic expertise — rapid tests made in France since 1991
- ISO 13485The international quality-management standard for organisations that design, manufacture and service medical devices
- Every batch checkedDefined checks completed before a batch is released
- Monitored after releasePerformance tracked for as long as the batch is on the market
Notified body 0483ISO 13485Made in FranceCE-marked IVD
The Patris Health promise. No valid result? Write to us and we replace the test or refund the purchase price. It applies whenever the test was performed as the instructions describe, and we do not argue about it.
Specification
Technical data for the CRP test
| Intended use | Semi-quantitative immunochromatographic screening test for C-reactive protein (CRP) in capillary whole blood, for self-testing by lay users |
|---|---|
| Analyte | C-reactive protein (CRP) |
| Method | Lateral flow immunoassay |
| Ranges | Below 8 · 8 to 40 · 40 to 100 · above 100 mg/L (WHO reference) |
| Sample | Capillary whole blood from a fingertip, diluted in the vial provided |
| Time to result | Read at 5 minutes; do not interpret after 10 minutes |
| Agreement | 99.15 % overall agreement with reference methods (95 % CI 95.07–100 %) |
| Storage | 4 to 30 °C, do not freeze |
| Expiry date | Indicated on the label and the foil pouch |
| Device type | CE-marked in-vitro diagnostic medical device (IVD) for self-testing |
| Certificates | CE 0483 · ISO 13485 |
Questions
Asked before ordering
How accurate is a CRP test at home compared with the laboratory?+
In the evaluation studies, the test agreed with laboratory reference methods in 99.15 % of cases (95 % CI 95.07–100 %). The difference is what you get back: the laboratory reports a CRP number, this test places you in one of four ranges. For deciding whether to see a doctor, the range is what matters.
Can it tell a viral from a bacterial infection?+
Not for certain. The test shows how high your CRP is. The higher the level, the more likely a severe bacterial infection. The diagnosis itself is your doctor’s.
Does the finger prick hurt?+
It is a brief prick. Wash your hands with warm water first, massage the finger towards the tip for 10 to 15 seconds, and prick the side of the fingertip. The needle retracts into the lancet straight away.
Why does the blood go into the vial and not onto the test device?+
In this test the blood must be diluted before it reaches the strip. The pipette collects the right amount of blood and the vial holds the right amount of diluent. The result is accurate only if both amounts are correct, so follow the quantities exactly.
Do medicines affect the result?+
Statins and fibrates can lower a raised CRP, and oral hormone therapy for the menopause can raise it. If you take any of these, tell your doctor when you show the result.
What if I cannot get enough blood?+
Massage the finger gently from its base towards the tip, with a light squeeze-and-release motion, until a large drop forms. Then fill the pipette to the line. Every kit has a spare lancet and pipette for a second attempt.
The lancet did nothing when I pressed it+
A lancet works only once. If the grey protective cap was pulled off by force instead of twisted, the lancet may already have been triggered. Take the spare lancet, give the cap a quarter turn, keep turning until it comes away, then press the lancet firmly against the side of the fingertip and press the trigger button.
How do I dispose of the lancet?+
The needle retracts into the lancet body after use, so all components can go in household waste. If your pharmacy collects sharps separately, use that; it is the tidier option.
Sources
National Institute for Health and Care Excellence. (2025, September 2). Suspected acute respiratory infection in over 16s: Assessment at first presentation and initial management (NICE guideline NG237). https://www.nice.org.uk/guidance/ng237/chapter/Recommendations
National Library of Medicine. (2025, June 11). C-reactive protein (CRP) test. MedlinePlus. https://medlineplus.gov/lab-tests/c-reactive-protein-crp-test/
Singh, B., Goyal, A., & Patel, B. C. (2025). C-reactive protein: Clinical relevance and interpretation. In StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK441843/
Sproston, N. R., & Ashworth, J. J. (2018). Role of C-reactive protein at sites of inflammation and infection. Frontiers in Immunology, 9, Article 754. https://doi.org/10.3389/fimmu.2018.00754
Last reviewed 2 October 2026
Instructions for use
Patris Health CRP Home Test
Detection of C-Reactive Protein in whole blood. CE-marked in-vitro diagnostic medical device for self-testing.
This is the English part of the multi-language instructions for use. The printed instructions in the box carry the same text in seven languages: English, German, French, Italian, Spanish, Dutch and Slovenian. If the version printed on the instructions in your box differs from this one, follow the instructions in your box.
Precautions and test components
Read this before you start: safety, storage and what is in the kit.
Testing procedure
Step by step, with a picture for each step.
Interpretation of the results
How to read your result, with pictures.
About the test
Background, questions and answers, accuracy.
Questions about the test: help@patris-health.com
Instructions for use CRPV02, January 2025 · © Patris Health. Copying and reproduction are not permitted.
