Insulin
The most thoroughly studied hormone in medicine and an essential therapy in type 1 diabetes. Also the single most dangerous compound on this list when used without medical supervision.
Metabolic & Weight
Glucagon
The body's own hormone for raising blood glucose, approved as an emergency treatment for severe hypoglycaemia. Well characterised and unambiguously effective for that use.
Overview
Glucagon is insulin's opposite number. When blood sugar falls, the pancreas releases it, and the liver responds by breaking down stored glycogen and releasing glucose into the bloodstream. As a medicine it is used to rescue someone whose blood sugar has crashed and who cannot safely swallow. It also relaxes smooth muscle, which is why radiologists use it during gut imaging.
A 29-amino-acid peptide cleaved from proglucagon in pancreatic alpha cells. Acts at the class B GPCR glucagon receptor, predominantly hepatic, coupling to Gs and raising cAMP/PKA, driving glycogenolysis and gluconeogenesis while inhibiting glycogenesis and glycolysis. Requires adequate hepatic glycogen stores, which is why it fails in starvation, chronic hypoglycaemia and alcohol-related states. Newer stable formulations (ready-to-use liquid autoinjector, nasal powder) avoid the reconstitution step that made older kits unreliable in an emergency.
Research areas
Hypoglycaemia rescueDiabetes managementGastrointestinal imaging
Dosing reported in the literature
Every protocol below is reproduced from a published study or approved labelling, with its source named. These are records of what was studied — not recommendations, and not a suggestion that any of them is appropriate for any person.
| Protocol as reported | Source |
|---|---|
| 1 mg subcutaneously or intramuscularly for severe hypoglycaemia in adults and children over 25 kg | Approved product labelling |
| 3 mg as a single intranasal dose in one nostrilDoes not require inhalation — absorption is across the nasal mucosa. | Nasal glucagon labelling |
Trial status
Approved and in routine clinical use for decades. Modern formulations supported by their own registration trials.
Reported safety signals
- Nausea and vomiting after administration are common; positioning matters if the person is unconscious.
- Ineffective when hepatic glycogen is depleted — starvation, adrenal insufficiency, chronic hypoglycaemia, or alcohol-related hypoglycaemia.
- Contraindicated in phaeochromocytoma and insulinoma.
- It is a rescue medication, not a metabolic enhancer; using it outside hypoglycaemia has no rationale and carries real risk.
Common questions
Why do some new obesity drugs deliberately activate the glucagon receptor?
Because glucagon also increases energy expenditure and hepatic fat oxidation. Dual and triple agonists like survodutide and retatrutide pair glucagon receptor activity with GLP-1 activity, so the GLP-1 arm offsets the glucose-raising effect while the glucagon arm adds energy expenditure.
Primary sources
Medical disclaimer
This page is for informational and research purposes only. Nothing here constitutes medical advice. The compounds discussed are research chemicals. Consult a qualified clinician before starting any protocol.
How this profile was built →