C-peptide (Serum) – Mass Concentration
This test measures the amount of C-peptide, a natural substance produced by your pancreas along with insulin during digestion. It helps assess how well your pancreas is making insulin.
["C-peptide helps evaluate insulin production and diabetes management."]
Key facts at a glance
- LOINC
- 95086-5
- Short code
- C peptide 30M p meal SerPl-mCnc
- Synonyms
- C peptide 30M p meal SerPl-mCnc
- Category
- coagulation
- Sample
- serum
- Container
- Red-top tube (SST)
- 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
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why is this test done?
Your doctor may order a C-peptide test to check if your pancreas is producing insulin normally. It can help diagnose or monitor conditions like diabetes, especially when insulin levels alone may not be reliable. This test is also used to distinguish between types of diabetes or to assess how well insulin therapy is working.
What does a result mean?
Results can indicate whether your body produces insulin independently (as in type 1 diabetes) or if insulin is being produced but not effectively used (as in type 2 diabetes). Abnormal levels may suggest issues with insulin production or function, but interpretation depends on clinical context and other test results.
How is the test collected?
A blood sample is drawn from a vein, usually in your arm. You may feel a small pinch when the needle is inserted, but the procedure is quick. You can eat and drink normally before the test unless your doctor advises otherwise.
What should I do before the test?
No special preparation is needed for this test. However, inform your doctor about any medications you’re taking, especially those that might affect blood sugar or insulin levels. Avoid eating or drinking anything for 8–12 hours before the test if fasting is required (though fasting isn’t typically required for C-peptide).
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 testing is critical for diagnosing and managing diabetes. Low levels may indicate type 1 diabetes, where the pancreas produces little to no insulin. High levels could suggest insulin resistance or overproduction, but results must be evaluated alongside symptoms, other tests, and medical history. It’s also useful in monitoring insulin therapy effectiveness or detecting pancreatic dysfunction.
Short name
C-peptide level
Frequently asked questions
How long does it take to get results?
What if my results are out of the usual range?
Can I eat or drink before 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