C-peptide measured after a high-protein meal (serum/plasma)
This test evaluates how your pancreas releases C-peptide, a natural marker of insulin production, after eating a meal high in protein. It helps assess your body’s ability to manage blood sugar post-meal.
["Assesses insulin production and meal-related blood sugar response."]
Key facts at a glance
- LOINC
- 95089-9
- Short code
- C peptide 4h p meal SerPl-mCnc
- Synonyms
- C peptide 4h 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 healthcare provider may order this test if you have diabetes, prediabetes, or suspected insulin resistance. It can also help monitor how well your pancreas functions after eating, especially if you’re on insulin therapy or have conditions like type 1 or type 2 diabetes.
What to Expect Before the Test
You’ll fast for a set period before the test (usually overnight) and then eat a meal rich in protein. Blood will be drawn at specific times to measure C-peptide levels. Follow your provider’s instructions carefully to ensure accurate results.
How the Test Works
Blood is collected from a vein in your arm at different times after the meal. The test measures C-peptide, a substance produced by your pancreas along with insulin. Unlike insulin, C-peptide stays in your blood longer, making it useful for assessing insulin production.
What the Results Mean
Results help determine if your pancreas produces enough insulin after eating. Low levels may indicate poor pancreatic function, while abnormal patterns could signal diabetes, insulin resistance, or other metabolic issues.
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 critical for diagnosing and managing diabetes, assessing insulin sensitivity, and evaluating pancreatic health. It provides insight into how your body processes nutrients and maintains blood sugar levels, especially after meals.
Short name
Meal-stimulated C-peptide
Frequently asked questions
Why might my doctor recommend this test?
How long will I need to prepare for this test?
Can I take medications before the 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