PeptideHormone

Glucagon

The counter-regulatory hormone that raises blood glucose.

EndogenousEstablished

Identity

Class
Proglucagon-derived peptide (29 aa)
Source
Pancreatic islet alpha cells
Receptor
Glucagon receptor (GCGR), a class B GPCR

Key properties

Molecular weight
~3,482.8 Da
Half-life (native)
~3–6 min
Model dosing

Approximate values for the native hormone. Engineered analogs are often deliberately larger and far longer-acting.

Mechanism

Glucagon opposes insulin: in fasting or hypoglycemia it drives hepatic glycogenolysis and gluconeogenesis to raise blood glucose. It also increases energy expenditure, which is why glucagon agonism is explored as a component of triple co-agonists.

Reference notes

  • Glucagon and GLP-1 are both cleaved from the same proglucagon precursor, tissue-specifically.
  • Its energy-expenditure effect is the rationale for including controlled glucagon agonism in some metabolic candidates.
  • Counter-regulation makes glucagon central to understanding hypoglycemia.

Selected literature

Curated peer-reviewed reviews, sourced from PubMed. Selected for relevance, not exhaustive — open any entry on PubMed for the full record and its primary citations.

  1. 1.The New Biology and Pharmacology of Glucagon · Physiological reviews, 2017 · PMID 28275047
  2. 2.100 years of glucagon and 100 more · Diabetologia, 2023 · PMID 37367959
  3. 3.Glucagon and regulation of glucose metabolism · American journal of physiology. Endocrinology and metabolism, 2003 · PMID 12626323