Glucagon

GlucaGen / Baqsimi / Gvoke

Glucagon is the hormone that opposes insulin. Released by the alpha cells of the pancreas when blood sugar falls, this 29–amino-acid peptide signals the liver to break down stored glycogen (glycogenolysis) and make new glucose (gluconeogenesis), raising blood glucose back toward normal. Together, insulin and glucagon form the body's main system for keeping blood sugar in a safe range. As a medicine, glucagon's headline use is as an emergency rescue for severe hypoglycemia — a dangerously low blood sugar in a person (often with diabetes on insulin) who is confused, unconscious, or unable to swallow safely, and therefore cannot take sugar by mouth. A glucagon injection or nasal dose rapidly prompts the liver to release glucose and buy time. Traditional emergency kits (GlucaGen) require reconstituting a powder with a syringe; newer ready-to-use options have made rescue far simpler — Baqsimi is a nasal powder that needs no injection, and Gvoke is a pre-filled stable liquid autoinjector or pen. A separate analog, dasiglucagon, provides a stable ready-to-use liquid as well. Glucagon has other medical uses too: it relaxes smooth muscle, so it is used to slow the gut during certain imaging procedures, and it is used diagnostically and in some cases of beta-blocker or calcium-channel-blocker overdose. Its effect in hypoglycemia depends on the liver having glycogen stores, so it may work poorly in starvation, prolonged fasting, or alcohol-related lows. Glucagon is a prescription medicine; families and caregivers of people at risk of severe lows are often trained to give it. It treats an emergency and does not replace ongoing diabetes management.