Glucagon

also known as: GlucaGen, Baqsimi, Gvoke

The endogenous counter-regulatory hormone to insulin — FDA-approved for severe hypoglycemia (injectable GlucaGen, nasal Baqsimi, autoinjector Gvoke). Also the pharmacological template for GLP-1/glucagon dual agonists like Pemvidutide and Retatrutide.

A 29-amino-acid pancreatic α-cell peptide hormone that opposes insulin by stimulating hepatic glycogenolysis and gluconeogenesis; FDA-approved for the rescue treatment of severe hypoglycemia and as a diagnostic aid in endocrine imaging, and the structural and pharmacological template for the glucagon-receptor agonist arm of GLP-1/glucagon dual and triple agonists currently in late-stage development.

Mechanism of action

Binds the glucagon receptor (a class B GPCR) on hepatocytes, activating adenylyl cyclase, raising cAMP, and driving phosphorylase-mediated glycogenolysis and the gluconeogenic program. The acute rise in blood glucose reverses severe hypoglycemia. Chronic partial glucagon-receptor agonism is the basis for the "energy-expenditure arm" of GLP-1/glucagon dual agonists such as pemvidutide, cotadutide, and the glucagon component of retatrutide.

Primary uses

Severe hypoglycemia (rescue)
Diagnostic adjunct in gastrointestinal and endocrine imaging
Research template for glucagon-receptor agonism in dual/triple agonist development

Typical dosing

1 mg (injectable) or 3 mg (nasal) as needed for hypoglycemic emergency (subcutaneous, intramuscular, or intranasal)

Rescue dosing only; not a maintenance medication.

Regulatory status

FDA-approved in multiple formulations: GlucaGen (injectable, Novo Nordisk), Baqsimi (nasal powder, Amphastar/Lilly, 2019), Gvoke (subcutaneous autoinjector, Xeris, 2019). Indicated for severe hypoglycemia and as a diagnostic aid.

References

[fda-pi] GlucaGen (glucagon) Prescribing Information. Novo Nordisk.
[fda-pi] Baqsimi (glucagon) Prescribing Information. Amphastar Pharmaceuticals.
[fda-pi] Gvoke (glucagon) Prescribing Information. Xeris Biopharma.

Related peptides

Semaglutide

A once-weekly GLP-1 receptor agonist FDA-approved for type 2 diabetes and chronic weight management.

Retatrutide

An investigational triple hormone agonist that produced ~24% weight loss at 48 weeks in Phase 2 — the largest in any single-agent obesity trial to date.

Pemvidutide

Altimmune's GLP-1 / glucagon co-agonist — received FDA Breakthrough Therapy Designation for MASH in January 2026 after positive IMPACT Phase 2b antifibrotic data, with Phase 3 initiation planned for 2026.

Disclaimer

This entry is for educational purposes only and does not constitute medical advice. Dosing information reflects published regulatory or research data and is not a recommendation. Many compounds described here are not approved for human use in the United States. Consult a licensed medical professional before considering any peptide therapy.