C-peptide (Serum/Plasma)
This test measures the amount of C-peptide, a small protein produced by your pancreas along with insulin during digestion. It helps assess how well your pancreas is producing insulin naturally.
["C-peptide helps evaluate insulin production and diabetes management."]
Key facts at a glance
- LOINC
- 47834-7
- Short code
- C peptide 8M p Gc SerPl-sCnc
- Synonyms
- C peptide 8M p Gc SerPl-sCnc
- 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?
Doctors may order a C-peptide test to check if your pancreas is making enough insulin. It can help diagnose diabetes, monitor treatment for diabetes, or determine if you have a condition called insulinoma, where the pancreas makes too much insulin.
How Is the Sample Collected?
A blood sample is taken from a vein in your arm. You may feel a small pinch when the needle is inserted, but it usually doesn’t cause much discomfort. The blood sample is sent to a lab for testing.
What Does the Test Result Mean?
Your result shows the concentration of C-peptide in your blood. High levels may suggest overproduction of insulin, while low levels could indicate insufficient insulin production. Your doctor will interpret the result in relation to your symptoms and medical history.
Common Reasons for Testing
Tests for C-peptide are often done when diagnosing or managing diabetes, checking for insulin-producing tumors, or evaluating how well your pancreas functions after surgery or treatment for conditions like pancreatitis.
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.
◆Associated findings1
Short name
C-peptide level
Frequently asked questions
What does a C-peptide test tell me about my diabetes?
How long does it take to get my C-peptide test results?
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