C-peptide

Definition

A protein fragment released by the pancreas in 1:1 ratio with endogenous insulin. Used clinically to distinguish patients still producing insulin (type 2 diabetes, prediabetes) from those who are not (type 1 diabetes, end-stage type 2). GLP-1 agonists work by augmenting endogenous insulin secretion — patients with very low C-peptide (<0.6 ng/mL) typically respond poorly, which is one reason GLP-1s are FDA-labeled for type 2 (not type 1) diabetes.

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Definition curated by Weight Loss Rankings — sourced from FDA labels and peer-reviewed PubMed literature, never AI-generated summaries.

Related terms in Mechanism

• GLP-1 receptor
• GIP receptor
• Dual agonist
• Gastric emptying
• Food noise
• Triple agonist
• Amylin
• GLP-1 tachyphylaxis
• Non-peptide GLP-1 agonist
• A1C (glycated hemoglobin)
• MASH / MASLD
• TBWL (Total Body Weight Loss)
• eGFR (estimated glomerular filtration rate)
• Visceral adipose tissue (VAT)

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