Glucagon
Also known as: GlucaGen, Baqsimi, Gvoke, glucagon hydrochloride, glucagon recombinant, dasiglucagon, glucagon emergency kit, nasal glucagon, GCGR agonist
Pancreatic peptide hormone; counterregulatory hormone; antihypoglycemic agent; glucagon receptor agonist
What it is
Glucagon is the hormone diabetics carry for emergencies — an injectable or nasal powder that rapidly reverses dangerously low blood sugar when someone cannot eat or drink. Made naturally by the pancreas, it does the opposite of insulin: it signals the liver to release stored sugar. Multiple FDA-approved rescue forms exist, including a needle-free nasal powder.
The scientific side
glucagon is a 29-amino acid peptide hormone secreted by alpha cells of the pancreatic islets of Langerhans in response to falling blood glucose levels, amino acid ingestion, sympathetic nervous system activation, and other stimuli. Its primary physiologic role is to maintain glucose homeostasis by counteracting the anabolic, glucose-lowering effects of insulin. Glucagon acts through the glucagon receptor (GCGR), a class B G protein-coupled receptor (GPCR) with seven transmembrane-spanning domains. Upon binding, glucagon activates adenylyl cyclase, increasing intracellular cyclic AMP (cAMP), which in turn activates protein kinase A (PKA) and downstream signaling cascades. In the liver — the primary target organ — this signaling cascade activates glycogen phosphorylase to promote glycogenolysis (the breakdown of stored glycogen to glucose) and stimulates gluconeogenesis (de novo glucose synthesis from amino acids and other precursors), rapidly mobilizing glucose into the circulation. Beyond acute glucose mobilization, glucagon has important roles in lipid metabolism: it increases hepatic fatty acid oxidation and attenuates endogenous lipid synthesis, making it relevant to conditions such as metabolic dysfunction-associated steatohepatitis (MASLD/MASH). Glucagon also regulates amino acid catabolism — it stimulates hepatic uptake and oxidation of amino acids, reduces circulating amino acid levels, and plays a key role in gluconeogenesis from amino acid substrates. In adipose tissue and skeletal muscle, glucagon increases energy expenditure and thermogenesis via mechanisms that remain partially elucidated, possibly involving brown adipose tissue activation and uncoupling protein expression. At the pharmacologic level, ready-to-use formulations (Gvoke, Baqsimi) have been developed to overcome the instability of conventional lyophilized glucagon; the intranasal formulation (Baqsimi) achieves adequate bioavailability by absorption through the nasal mucosa without requiring reconstitution. The glucagon receptor is also being co-targeted with GLP-1 receptors in dual agonist approaches (e.g., survodutide, cotadutide) to leverage glucagon's thermogenic and lipid-oxidizing actions while mitigating its glucose-raising effects via the incretin component.
Class: Pancreatic peptide hormone; counterregulatory hormone; antihypoglycemic agent; glucagon receptor agonist
Administration & storage
- Administration
- Intramuscular injection (thighdeltoid) — standard for bystander/caregiver emergency useSubcutaneous injection — acceptable alternative route; slightly slower onsetIntravenous injection or infusion — used in clinical/hospital settings and diagnostic procedures; fastest onsetIntranasal powder (Baqsimi) — needle-freeno preparationsingle-use device3 mg per nostril
- Storage
- Unconstituted GlucaGen/Lilly kits: store at room temperature (15–25°C/59–77°F) or refrigerate (2–8°C); do not freeze. Gvoke prefilled syringe/autoinjector: refrigerate (2–8°C); may be stored at room temperature (up to 25°C/77°F) for up to 12 months; do not freeze. Baqsimi nasal powder: store at room temperature (20–25°C/68–77°F); protect from moisture.
- Cautions
- Nausea and vomiting are common after glucagon administration — position unconscious or semi-conscious patient on their side to prevent aspiration.,Glucagon is ineffective in states of depleted hepatic glycogen (prolonged fasting, starvation, adrenal insufficiency, chronic alcoholism) — IV glucose is required in these situations.,Transient hyperglycemia may occur after glucagon rescue; monitor blood glucose.,Patients with pheochromocytoma: glucagon stimulates catecholamine release from the tumor, which may cause severe hypertension — use with extreme caution or avoid.,Patients with insulinoma: glucagon may initially raise glucose but can subsequently trigger excess insulin secretion leading to rebound hypoglycemia.,Hypersensitivity reactions including anaphylaxis have been reported; epinephrine and resuscitation equipment should be available when glucagon is used in medical settings.,Cardiac: glucagon has positive inotropic and chronotropic effects at pharmacologic doses — use with caution in patients with known cardiac disease.
Legal & regulatory status
Multiple FDA-approved formulations: GlucaGen (Novo Nordisk, glucagon for injection, 1 mg/mL) approved for severe hypoglycemia rescue and diagnostic GI imaging. Glucagon Emergency Kit (Eli Lilly) approved 1998 for severe…
Glucagon is not listed on the current WADA Prohibited List. It is a prescription-only endogenous peptide hormone used exclusively for the emergency management of severe hypoglycemia and as a diagnostic agent. No…
Glucagon for injection (GlucaGen) is approved by Health Canada for treatment of severe hypoglycemia in diabetic patients and as a diagnostic aid for GI tract relaxation during radiological examinations. Intranasal…
What it's studied for
- Severe hypoglycemia rescue — FDA-approved injectable and intranasal formulations Phase III RCT / FDA-approved indication
- Diagnostic gastrointestinal imaging — bowel relaxation Established clinical use / approved indication
- Counterregulatory hormonal physiology in type 1 and type 2 diabetes — pathophysiology and therapeutic modulation Human RCT / mechanistic clinical study
- Dual GLP-1/glucagon receptor agonism — obesity and MASLD/MASH treatment Phase II RCT / investigational
- Energy expenditure and thermogenesis — investigational metabolic applications Preclinical / early human studies
- Stable liquid and nasal delivery formulations — formulation development Phase III RCT / clinical pharmacology
Safety signals
- Nausea and vomiting — risk of aspiration in unconscious patients
- Inefficacy in glycogen-depleted states
- Pheochromocytoma — hypertensive crisis
- Rebound hypoglycemia following glucagon rescue
- Cardiac effects at pharmacologic doses — tachycardia and positive inotropy
- Hypersensitivity reactions including anaphylaxis
Contraindications
About these dose ranges
Dose ranges below reflect commonly reported community protocols. Where published research cites a specific dose, the PMID is linked. Doses without citations are not clinical recommendations — they reflect what practitioners and researchers commonly report using.
Community-reported dosing
| Route | Dose | Frequency / Duration | Population / context | Source tier |
|---|---|---|---|---|
| Unspecified | 1 mg (1000 µg) | — | Adults and children ≥25 kg — severe hypoglycemia rescue | Research |
| Unspecified | 0.5 mg (500 µg) | — | Children <25 kg — severe hypoglycemia rescue | Research |
| Unspecified | 0.5–2 mg IV or IM | — | Adults — diagnostic GI imaging (bowel relaxation) | Research |
| Unspecified | 40–200 µg (mini-dose) | — | Adults — investigational mini-dose for closed-loop systems | Research |
| Intramuscular, subcutaneous, or intranasal | Adults: 1 mg IM/SC (Gvoke, GlucaGen) or 3 mg intranasal (Baqsimi); Children <25 kg: 0.5 mg IM/SC | Single emergency dose; may repeat once after 15 minutes if no response | Adults and children with diabetes or insulin-using patients at risk for severe hypoglycemia |