Glucagon
Also known as: GCG, Hyperglycemic factor, Emergency glucose peptide
Overview
Glucagon is a 29-amino acid pancreatic peptide hormone secreted by alpha cells of the islets of Langerhans in response to hypoglycemia. Its primary function is to counteract insulin by stimulating hepatic glycogenolysis and gluconeogenesis, raising blood glucose levels. In modern metabolic medicine, glucagon receptors are also implicated in energy expenditure, food intake, and lipid metabolism, making glucagon receptor agonism or modulation a component of multi-agonist weight loss therapeutics. Retatrutide, for example, is a triple GLP-1/GIP/glucagon agonist where the glucagon component contributes to energy expenditure enhancement.
Mechanism of Action
Glucagon binds the glucagon receptor (GCGR), a class B GPCR, activating adenylyl cyclase (cAMP/PKA pathway) in hepatocytes to phosphorylate glycogen phosphorylase (activating glycogenolysis) and inhibit glycogen synthase. In adipocytes, cAMP-mediated PKA phosphorylates hormone-sensitive lipase, stimulating lipolysis. In the hypothalamus, glucagon receptor signaling promotes satiety and energy expenditure. In combination metabolic agonists (GLP-1/glucagon), the glucagon component counteracts GLP-1's hypoglycemic tendency and adds thermogenic/lipolytic activity.
Potential Benefits
- Emergency hypoglycemia reversal (FDA approved)
- Hepatic glycogenolysis and gluconeogenesis stimulation
- Component of multi-agonist metabolic therapies enhancing energy expenditure
- Lipolytic activity in adipose tissue
- Satiety signaling in central nervous system
Dosage Protocols
The following reflects doses used in published research studies. This is not medical advice. Consult a qualified healthcare professional.
| Beginner | 1 mg IM/SC for severe hypoglycemia (standard emergency kit) |
| Intermediate | Nasal glucagon (Baqsimi) 3 mg intranasal for hypoglycemia |
| Advanced | Continuous infusion only in clinical/research settings |
| Cycle Duration | Acute emergency use |
FDA-approved for severe hypoglycemia (Glucagon Emergency Kit, Gvoke, Baqsimi, Zegalogue). Opposes insulin action.
Use our Reconstitution Calculator to determine exact syringe units for your protocol.
Routes of Administration
Intramuscular / Subcutaneous Injection High
Standard emergency hypoglycemia kit.
Intranasal (Baqsimi) ~9% — but sufficient for rescue
FDA-approved needle-free rescue device.
Intravenous 100%
Hospital use — faster onset.
Read our full Routes of Administration Guide for detailed comparison of all delivery methods.
Stacking Protocols
Popular research stacks involving Glucagon:
Not Applicable — Emergency Agent
Glucagon is an emergency counter-regulatory hormone, not used in stacking. Long-acting glucagon analogs are in development for glycemic stability in T1D (bi-hormonal closed-loop).
Explore our complete Peptide Stacking Guide for more combinations and safety considerations.
Reconstitution
| Storage | Store kit at room temperature 20-25°C. Use immediately after mixing. |
|---|
Older vial+syringe kits require reconstitution; newer Gvoke/Zegalogue are pre-filled.
Need exact syringe measurements?
Amino Acid Sequence
His-Ser-Gln-Gly-Thr-Phe-Thr-Ser-Asp-Tyr-Ser-Lys-Tyr-Leu-Asp-Ser-Arg-Arg-Ala-Gln-Asp-Phe-Val-Gln-Trp-Leu-Met-Asn-Thr-OH
Side Effects & Safety
- Nausea and vomiting
- Hyperglycemia if excessive dosing
- Hypokalemia at high doses
Safety & Contraindications
This information is for educational purposes only. Consult a qualified healthcare provider before using any peptide.
Bleeding Disorders
Active Skin Infection at Injection Site
FDA Safety Information
FDA labeling warns of hypersensitivity reactions and necrolytic migratory erythema with prolonged use; use with caution in insulinoma, pheochromocytoma, and glucagonoma.
Pharmacokinetics
| Half-Life | ~3-6 minutes |
|---|---|
| Storage | Store at controlled room temperature 20-25°C. Protect from light. |
Synergistic Compounds
The following compounds have been studied alongside Glucagon for potential complementary or synergistic effects:
Learn More
References & Further Reading
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