C-Peptide
C-peptide is a blood marker that shows how much insulin your pancreas is actually producing — it helps doctors pinpoint the true cause of high blood sugar.
Plain English
Patient-Friendly Explanation
C-peptide is a small piece of the insulin molecule that is released into the blood when the body makes insulin. Measuring it shows how much insulin your pancreas is actually producing. This helps doctors tell apart different causes of high blood sugar.
Medical
Clinical Definition
C-peptide is a 31-amino-acid peptide cleaved from proinsulin during insulin biosynthesis and secreted equimolarly with insulin; it serves as a stable marker of endogenous pancreatic beta-cell secretion. Fasting or stimulated C-peptide levels help distinguish type 1 from type 2 diabetes, guide decisions on insulin therapy, and — in people with obesity — help determine whether hyperinsulinaemia reflects true hypersecretion or reduced insulin clearance. Low C-peptide with high glucose indicates beta-cell failure; high C-peptide with high glucose indicates severe insulin resistance.
Key Insight
Why It Matters
A C-peptide test gives a clearer picture of your pancreas than blood sugar alone, and it can change the treatment plan for weight-related diabetes. It is one of the metabolic checks we may recommend before starting a programme.
Sources
Reviewed against standard medical references.
Medically reviewed by
Family Physician & Registered Acupuncturist, Accord Medical Clinic. MBBS (NUS), Graduate Diploma in Family Medicine (NUS), Graduate Diploma in Acupuncture (Singapore College of TCM).
Last reviewed: September 2026
This page is general health education, not medical advice. Whether any treatment is appropriate for you is a decision made in consultation after assessment.
