C-peptide (Serum or Plasma, Mass Concentration)
This test measures the amount of C-peptide, a small protein produced along with insulin during blood sugar regulation. It helps assess how much insulin your pancreas naturally makes.
["C-peptide helps doctors evaluate insulin production and diagnose conditions like diabetes or pancreatic issues."]
Key facts at a glance
- LOINC
- 47832-1
- Short code
- C peptide 4M p 1 mg Gc SerPl-sCnc
- Synonyms
- C peptide 4M p 1 mg 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
What Is C-Peptide Used For?
C-peptide is primarily used to distinguish between types of diabetes and to check if your pancreas is producing insulin. It can also help monitor how well insulin is being made in people with diabetes.
How Is the Test Performed?
A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where it is analyzed using a specialized test to measure C-peptide levels.
Why Might You Need This Test?
Your doctor may order this test if you have symptoms of diabetes, if your blood sugar levels are hard to control, or if you have questions about your pancreas’s function, such as whether you’re producing insulin normally.
What Do My Results Mean?
Results can help determine if you have type 1 or type 2 diabetes, if your pancreas is working as expected, or if you’re taking insulin from an external source (like injections). High or low levels may signal underlying health concerns.
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: C-peptide levels are critical for diagnosing diabetes and assessing insulin production. In type 1 diabetes, C-peptide is usually low because the pancreas stops producing insulin. In type 2 diabetes, C-peptide can be normal or slightly elevated, depending on how much insulin the body still makes. It’s also useful in pregnancy to check for gestational diabetes and in evaluating pancreatic diseases.
Short name
C-peptide level
Frequently asked questions
What causes abnormal C-peptide levels?
How often should I get this test?
Can lifestyle changes affect C-peptide levels?
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