C-peptide (Serum or Plasma) with High-Performance Liquid Chromatography (HPLC) Measurement
This test measures the amount of C-peptide, a small protein produced along with insulin when your pancreas releases it. It helps assess how much insulin your body naturally makes.
["C-peptide helps evaluate your pancreas’s insulin production and can support diabetes management."]
Key facts at a glance
- LOINC
- 13039-3
- Short code
- C peptide 1h p chal SerPl-mCnc
- Synonyms
- C peptide 1h p chal 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 This Test Is Done
Doctors may order a C-peptide test to check if your pancreas is producing enough insulin. It’s often used in people with diabetes to confirm whether their condition is caused by insulin deficiency (like type 1 diabetes) or insulin resistance (like type 2 diabetes). It can also help monitor treatment effectiveness or diagnose other conditions affecting insulin production.
How the Test Works
A small blood sample is taken from a vein in your arm. The sample is processed to separate and measure C-peptide levels using high-performance liquid chromatography (HPLC), a precise method that detects tiny amounts of this protein.
What to Expect Before the Test
No special preparation is needed for this test. You may have some mild discomfort from the needle, but it usually goes away quickly. If you’re on blood thinners, let your doctor know before the test.
What the Results Mean
Results help determine if your pancreas is working as expected. Low levels may suggest insulin deficiency, while normal or high levels could indicate other health factors. Your doctor will discuss these results in the context of your overall health.
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 diabetes subtypes, guiding treatment plans, and assessing pancreatic function. It can also help rule out conditions like insulinoma (a rare tumor that causes excessive insulin production) or other metabolic disorders. Doctors use these results to tailor therapies, such as insulin therapy or lifestyle changes, to improve long-term health outcomes.
Short name
C-peptide test
Frequently asked questions
How long does it take to get my C-peptide test results?
Can I eat or drink before this test?
Is there any risk or side effect from this blood 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