Glucagon was a naturally-occurring hormone in Humans. Administered as a drug, glucagon was used to treat hypoglycemia or beta-blocker overdoses. Glucagon caused glycogenolysis, a breakdown of glycogen stored in the liver into glucose. In 2024, Doctor Bashir tried to get Lee some GlucaGen (a trade name brand of glucagon widely available in the 20th and 21st century). (DS9: "Past Tense, Part II")