C-Peptide
C-Peptide is a protein released by the pancreas alongside insulin. It measures how much insulin your body is producing on its own.
Category: Diabetes & Glycemic
Also known as: c-peptide, c peptide, connecting peptide, Connecting peptide of insulin, Pro-insulin c peptide, c-peptid
Reference range: 0.8–3.8 ng/mL (Source: ABIM)
Standard unit: ng/mL
High values may indicate
High C-Peptide levels may indicate insulin resistance, type 2 diabetes, insulinoma (insulin-producing tumor), or Cushing's syndrome.
Low values may indicate
Low C-Peptide levels may indicate type 1 diabetes, late-stage type 2 diabetes, or that insulin production by the pancreas is significantly reduced.
Frequently asked questions
- What is a normal C-Peptide level?
- A typical reference range for C-Peptide is 0.8–3.8 ng/mL (source: ABIM). Reference ranges vary by laboratory, age, and sex, so always compare against the range on your own lab report.
- What units is C-Peptide measured in?
- C-Peptide is most commonly reported in ng/mL. Labs in different countries may use other units — you can convert between them with BloodId's blood test unit converter.
- Where do C-Peptide reference ranges come from?
- BloodId uses ABIM standard reference ranges and educational information from MedlinePlus (see our methodology). Reference ranges still vary by lab, age, and sex, so always compare against your own report.
- Can I track C-Peptide over time?
- Yes. Upload results from any lab and BloodId charts your C-Peptide over time against its reference range, so you can see whether the trend is rising, falling, or stable.
Related biomarkers
Source: MedlinePlus, U.S. National Library of Medicine
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