: C-Peptide, 24-Hour Urine, Mass Concentration
: This test measures the total amount of C-peptide released in your urine over a 24-hour period. C-peptide is a byproduct of insulin production and helps show how well your pancreas is making insulin.
[": A 24-hour urine C-peptide test estimates your body's overall insulin production over a full day."]
Key facts at a glance
- LOINC
- 55920-3
- Short code
- C peptide 24h Ur-mCnc
- Synonyms
- C peptide 24h Ur-mCnc
- Category
- coagulation
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85610
- SNOMED
- 396252006
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
: What Is C-Peptide?
: C-peptide is a small protein released together with insulin when your pancreas produces insulin. Because insulin leaves the bloodstream quickly but C-peptide lasts longer and is cleared in urine, measuring C-peptide over 24 hours gives a broader picture of how much insulin your body is making.
: How the 24-Hour Collection Works
: For this test you collect all of your urine over a full 24-hour period in a special container, following instructions from your lab. The container is then sent to the laboratory, where the total C-peptide concentration is measured and combined with the collection volume to estimate your daily output.
: Why Your Clinician May Order It
: Your clinician may order this test to help evaluate how much insulin your pancreas is producing, to investigate low blood sugar episodes, or to help distinguish between different causes of diabetes. It is often used along with blood glucose and other hormone tests.
: Preparing for the Test
: Follow your laboratory's instructions for the 24-hour collection carefully, including when to start and stop and how to store the container. Tell your clinician about any medicines, supplements, or health conditions you have, as some can affect results.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
: C-peptide reflects endogenous insulin secretion. A 24-hour urine measurement can help assess overall pancreatic beta-cell function and support evaluation of hypoglycemia or classification of diabetes, but it is interpreted together with blood glucose, insulin, and clinical findings; results should be discussed with your clinician.
Short name
: 24h Urine C-Peptide
Frequently asked questions
: Do I need to fast for a 24-hour urine C-peptide test?
: What happens if I miss part of the urine collection?
: Can medicines affect the result?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy