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approvedWeight Loss & Diabetes

Glucagon

Also known as: GlucaGen, Baqsimi, Gvoke, Glucagon HypoKit

Glucagon is a 29-amino-acid peptide hormone produced by pancreatic alpha cells that serves as the primary counter-regulatory hormone to insulin. FDA-approved since 1960 for the emergency treatment of severe hypoglycemia, it is a cornerstone of diabetes emergency management. Glucagon acts on hepatic glucagon receptors to stimulate glycogenolysis and gluconeogenesis, rapidly raising blood glucose. Beyond its established role, glucagon receptor agonism is a key component of next-generation multi-agonist obesity therapies including survodutide and retatrutide.

3 cited references·5 researched benefits

Quick Answer

Glucagon is a 29-amino-acid pancreatic hormone that is the primary counter-regulatory signal to insulin, raising blood glucose through hepatic glycogenolysis and gluconeogenesis. FDA-approved for emergency hypoglycemia treatment, it is available as injection (GlucaGen, Gvoke) and nasal powder (Baqsimi). Glucagon receptor agonism is now a key target in next-generation obesity drugs like survodutide and retatrutide, where it boosts energy expenditure and lipid oxidation.

Key Facts

Mechanism
Glucagon is secreted from pancreatic alpha cells in response to low blood glucose, amino acids, and sympathetic activation. It binds the glucagon receptor (GCGR), a class B GPCR on hepatocytes, activating Gs-adenylyl cyclase-cAMP-PKA signaling. This stimulates glycogenolysis (glycogen breakdown to glucose-1-phosphate) and gluconeogenesis (de novo glucose synthesis from lactate, amino acids, and glycerol) while inhibiting glycogenesis and glycolysis. In adipose tissue, glucagon promotes lipolysis and thermogenesis. Hepatic fatty acid oxidation is upregulated, reducing liver fat. In the heart, glucagon has positive inotropic and chronotropic effects. The glucagon-insulin axis is the fundamental regulator of fasting glucose homeostasis.
Research Status
approved
Half-Life
~8–18 minutes
Molecular Formula
C₁₅₃H₂₂₅N₄₃O₄₉S
Primary Use
Weight Loss & Diabetes
Table of Contents

Benefits

  • Emergency hypoglycemia reversal — raises blood glucose by 30–100 mg/dL within 10–20 minutes; lifesaving in severe insulin-induced hypoglycemiastrong
  • GI diagnostic applications — relaxes smooth muscle for endoscopy, barium studies, and CT/MRI imaging of the GI tractstrong
  • Energy expenditure increase — glucagon receptor agonism boosts hepatic energy expenditure and thermogenesis (basis for multi-agonist obesity drugs)strong
  • Hepatic fat reduction — glucagon signaling promotes fatty acid oxidation, reducing hepatic steatosis in preclinical and clinical studiesmoderate
  • Beta-blocker overdose treatment — positive inotropic effects independent of beta-adrenergic receptors; used in severe beta-blocker toxicitymoderate

Dosage Protocols

RouteDosage RangeFrequencyNotes
Intramuscular/subcutaneous injection (emergency hypoglycemia)1 mg (adults), 0.5 mg (children <25 kg)Single dose; may repeat in 15 minutes if no responseGlucaGen HypoKit and generic kits require reconstitution before injection. Gvoke HypoPen is a pre-filled auto-injector that does not require reconstitution. Administer immediately for severe hypoglycemia with loss of consciousness.
Intranasal powder (Baqsimi)3 mgSingle dose into one nostrilFDA-approved in 2019. No reconstitution or injection required — absorbed through nasal mucosa. Equally effective as injectable glucagon. Preferred by caregivers and patients for ease of use. Shelf-stable at room temperature.
Intravenous/intramuscular (GI diagnostic)0.25–2 mgSingle dose before procedureUsed to relax GI smooth muscle during endoscopy, barium swallow/enema, and abdominal CT/MRI. Duration of smooth muscle relaxation: ~15 minutes (IV) to ~25 minutes (IM).

Medical disclaimer

Dosage information is provided for educational reference only. Always follow your prescriber's instructions and consult a qualified healthcare provider before starting any peptide protocol.

Side Effects

  • Nausea and vomiting — occur in 25–35% of patients receiving emergency glucagon, typically after consciousness is regainedcommon
  • Hyperglycemia — excessive glucose elevation is possible, particularly in patients with adequate glycogen storescommon
  • Headache — reported in 10–20% of recipients following emergency administrationcommon
  • Allergic reactions — rare hypersensitivity reactions including rash, urticaria, and anaphylaxisrare
  • Ineffective in glycogen-depleted states — fails to raise glucose in patients with depleted hepatic glycogen (starvation, chronic alcoholism, adrenal insufficiency)serious

Frequently Asked Questions

Why is glucagon included in next-generation obesity drugs like survodutide and retatrutide?
Glucagon receptor agonism in combination with GLP-1 (and GIP in retatrutide) creates complementary weight loss mechanisms. While GLP-1 reduces appetite and food intake, glucagon increases hepatic energy expenditure, promotes fatty acid oxidation, reduces liver fat, and enhances thermogenesis. The combination produces greater weight loss than GLP-1 alone. Survodutide (GLP-1/glucagon dual agonist) achieved ~19% weight loss in phase 2 trials. The key challenge is balancing glucagon's hyperglycemic effect against GLP-1's glucose-lowering — in dual agonists, GLP-1 counteracts the hyperglycemia.
What is the difference between Baqsimi, Gvoke, and traditional glucagon kits?
Traditional glucagon emergency kits (GlucaGen HypoKit) require reconstitution — mixing lyophilized glucagon powder with diluent before injection, which is difficult during emergencies. Gvoke HypoPen (approved 2019) is a pre-filled auto-injector requiring no reconstitution — simply inject. Baqsimi (approved 2019) is an intranasal powder requiring no injection at all — simply administer into one nostril. Both newer formulations are shelf-stable at room temperature. Studies show caregivers successfully administer Baqsimi and Gvoke significantly faster than traditional kits.
How does glucagon relate to the bihormonal artificial pancreas?
The bihormonal (dual-hormone) artificial pancreas uses both insulin and glucagon delivered by closed-loop algorithms to maintain blood glucose. When glucose drops, the system delivers micro-doses of glucagon to prevent hypoglycemia — mimicking the physiological alpha cell response that is impaired in type 1 diabetes. Clinical trials show dual-hormone systems reduce hypoglycemia by 30–50% compared to insulin-only systems. Stable, room-temperature glucagon formulations (dasiglucagon) were developed specifically to enable this technology.
Can glucagon be used for food bolus esophageal obstruction?
Glucagon has been widely used off-label at 1 mg IV to relax esophageal smooth muscle for food bolus impaction (food stuck in the esophagus). However, systematic reviews show only 12–50% success rates, and the American Society for Gastrointestinal Endoscopy does not recommend routine use, preferring endoscopic removal. Glucagon may be attempted while arranging endoscopy but should not delay definitive intervention. The mechanism relies on lower esophageal sphincter relaxation, which is less effective for mid-esophageal impaction.

References

  1. 1
    Glucagon physiology and pathophysiology in the light of current and prospective therapies(2012)PubMed ↗
  2. 2
    Glucagon receptor agonism in the treatment of obesity and diabetes(2016)PubMed ↗
  3. 3
    Intranasal glucagon (Baqsimi) for severe hypoglycemia(2019)PubMed ↗

Latest Research

Last updated: 2026-02-19