Low C-peptide: what it means
A C-peptide result below the normal range is considered low. Here is what a reduced C-peptide can point to, and when it is worth discussing with a doctor.
Reference range: Fasting 0.5–2.0 ng/mL; rises with carbohydrate intake. Interpreted alongside glucose.
Understand your full resultWhat a low C-peptide can mean
- Type 1 diabetes — autoimmune beta-cell destruction; classic finding is high glucose + low C-peptide.
- Long-standing type 2 diabetes — beta-cell exhaustion after years of compensation.
- Pancreatectomy, severe chronic pancreatitis — anatomic loss of beta cells.
- Surreptitious insulin use — exogenous insulin causes hypoglycaemia with suppressed C-peptide.
When to discuss with a doctor
C-peptide is ordered when the type of diabetes is unclear (adult-onset that doesn't behave like type-2, lean patient on insulin who 'might not need it'), or to investigate hypoglycaemia (insulinoma vs factitious insulin use). It's not part of routine diabetes monitoring — HbA1c handles that. Mediora.AI shows C-peptide against glucose so the pattern (preserved vs absent insulin reserve) is visible; the diabetes-type decision is endocrinology.
Conditions this can relate to
Keep reading
One value is a snapshot. Upload the full test to see every marker explained together.
Upload your test - freeMediora.AI is informational - interpretation, not a diagnosis. A single out-of-range value is common and often benign; always discuss decisions with your doctor.