24-Hour Urinary C-Peptide Concentration
This test measures the amount of C-peptide, a natural substance produced along with insulin during digestion, over a full day in your urine. It helps assess how much insulin your body is making.
["This test helps evaluate pancreatic function and insulin production over time."]
Key facts at a glance
- LOINC
- 25872-3
- Short code
- C peptide 24h Ur-sCnc
- Synonyms
- C peptide 24h Ur-sCnc
- 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
Why This Test Is Done
Your doctor may order this test if they suspect conditions like diabetes, pancreatic issues, or other metabolic disorders that affect insulin production. It can also be used to monitor long-term insulin secretion in certain medical situations.
What to Expect Before the Test
You’ll need to collect all urine produced in a 24-hour period in a special container. Typically, you’ll start the collection at a specific time (often midnight or the start of your doctor’s scheduled visit) and finish it the same way the next day. Drink plenty of fluids to help urine flow normally.
What Happens During the Test
After collecting the urine, it is sent to a lab for analysis. The lab measures the concentration of C-peptide in your urine sample using a sensitive immunoassay method.
What the Results Mean
Results are interpreted by your healthcare provider based on your medical history and symptoms. Higher-than-normal levels may suggest overproduction of insulin, while lower levels could indicate reduced pancreatic function. Exact values are not provided here as reference ranges vary by lab and clinical context.
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.
This test is particularly useful for diagnosing or monitoring conditions like insulinoma (a rare tumor that causes excessive insulin production) or assessing pancreatic beta-cell function in diabetes management. It can also help differentiate between types of diabetes or rule out other metabolic disorders.
Short name
C-Peptide Urine Test (24-hour)
Frequently asked questions
What does a high C-peptide level in urine mean?
What does a low C-peptide level in urine mean?
How often should I get this test?
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