Glucagon: Uses, Mechanism, and Reported Side Effects

Key takeaways

• Glucagon is FDA-approved to treat severe hypoglycemia in pediatric and adult patients with diabetes.
• It is also used as a diagnostic aid to temporarily inhibit gastrointestinal movement during radiologic exams.
• The hormone works by activating hepatic glucagon receptors to trigger glucose release from liver glycogen stores.
• More than 3,300 trials have been registered that involve glucagon or related glucose-regulation research.
• FAERS reports most commonly mention drug ineffectiveness, breathing difficulty, kidney injury, and low blood pressure.

What Glucagon Is

Glucagon is a peptide hormone classified as an antihypoglycemic agent and a gastrointestinal motility inhibitor. It raises blood glucose by acting on hepatic glucagon receptors, which stimulates the breakdown of stored glycogen in the liver and releases glucose into the bloodstream. This effect depends on the liver having adequate glycogen reserves to draw from. Beyond its glucose-raising action, glucagon also relaxes smooth muscle in the stomach, duodenum, small bowel, and colon.

What Glucagon Is Approved For

Glucagon for Injection, marketed under the brand name Glucagon, carries two approved indications. The first is treatment of severe hypoglycemia in pediatric and adult patients with diabetes mellitus. The second is use as a diagnostic aid during radiologic examinations, where it temporarily slows movement of the gastrointestinal tract in adult patients. The label does not carry a boxed warning.

What the Evidence Shows

More than 3,300 trials have been registered that touch on glucagon or related metabolic pathways. Among the sampled studies, a completed Phase 4 trial examined the effects of linagliptin added to empagliflozin on islet cell physiology. Another completed trial looked at slowly digestible carbohydrates and their effect on GLP-1 secretion, reflecting the broader research interest in glucose-regulating hormones alongside glucagon itself.

Reported Side Effects

Adverse event reports submitted to FAERS reflect counts of reported reactions, not confirmed incidence or direct causation. The most frequently reported term is drug ineffectiveness, followed by dyspnoea and acute kidney injury. Hypotension and hypoglycaemia also appear frequently, along with reports of condition aggravated, general toxicity, and nausea. These patterns span cardiovascular, renal, respiratory, and metabolic categories rather than clustering around a single organ system.