C-peptide measured after a meal (postprandial)
This test checks how your body produces insulin after eating. It helps assess your pancreas’s ability to release insulin naturally.
["This test helps evaluate how well your pancreas responds to food."]
Key facts at a glance
- LOINC
- 95081-6
- Short code
- C peptide 1.5h p meal SerPl-mCnc
- Synonyms
- C peptide 1.5h 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 post-meal C-peptide test to check for diabetes, insulin resistance, or other conditions affecting insulin production. It can also help diagnose or monitor conditions like type 1 or type 2 diabetes, especially if other tests are unclear.
How Is the Sample Collected?
A blood sample will be taken after you eat a meal. This ensures the test reflects your natural insulin response. You may be asked to fast before the meal, but not before the blood draw.
What Does the Test Measure?
C-peptide is a natural byproduct of insulin production. Unlike insulin, it stays in your blood longer and doesn’t depend on insulin’s removal by the kidneys or liver. This test measures its levels to gauge how much insulin your pancreas releases.
What Are Common Uses?
This test helps doctors determine if your diabetes is caused by insulin deficiency (type 1) or insulin resistance (type 2). It can also guide treatment decisions, such as whether you need insulin therapy or other medications.
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.
Clinical Significance: This test is particularly useful for distinguishing between type 1 and type 2 diabetes, as well as for monitoring conditions like pancreatic diseases or insulinoma (a rare tumor that causes excessive insulin production).
Short name
Post-meal C-peptide
Frequently asked questions
Why might my doctor recommend this test?
What does a high or low C-peptide level mean?
Do I need to fast 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