C-Peptide

MetabolicMetabolism & EnergyBlood

C-peptide is released 1:1 with insulin production. Unlike insulin, it is not cleared by the liver, making it a stable marker of endogenous insulin production.

Why it matters: Helps distinguish Type 1 (low C-peptide) from Type 2 diabetes (normal/high C-peptide). Used to evaluate insulinoma.

Reference Range
1.1 – 4.4ng/mL
1.1
4.4LowNormalHigh
Symptoms of Low C-Peptide
High blood sugar
Excessive thirst
Frequent urination
Unintended weight loss
Symptoms of High C-Peptide
Weight gain
Sugar cravings
Fatigue after meals
Brain fog
What Moves It

May increase with:

Insulin resistance
Type 2 diabetes
Insulinoma

May decrease with:

Type 1 diabetes
Late-stage type 2 diabetes
Pancreatectomy
Associated Conditions
Type 1 diabetesType 2 diabetesInsulinoma
Related Markers
InsulinGlucoseHbA1c
Common questions

What is C-Peptide?

C-peptide is released 1:1 with insulin production. Unlike insulin, it is not cleared by the liver, making it a stable marker of endogenous insulin production.

What might a high or low C-Peptide mean?

Helps distinguish Type 1 (low C-peptide) from Type 2 diabetes (normal/high C-peptide). Used to evaluate insulinoma.

What is the typical reference range for C-Peptide?

The general-population reference range shown here is 1.1 – 4.4 ng/mL. Reference ranges describe the general population and are not a personal target — discuss your results with your physician.

What can affect C-Peptide?

It may be higher with: Insulin resistance, Type 2 diabetes, Insulinoma. It may be lower with: Type 1 diabetes, Late-stage type 2 diabetes, Pancreatectomy.

More in Metabolic
GlucoseHbA1cHbA1c (IFCC)HOMA-IRInsulin

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