Which hormone is responsible for regulating blood glucose levels?

Insulin is the hormone primarily responsible for regulating blood glucose levels. It is produced by the beta cells of the pancreas and plays a crucial role in lowering blood glucose levels after meals. When food is consumed, glucose from the carbohydrates enters the bloodstream, prompting the pancreas to release insulin. Insulin facilitates the uptake of glucose into cells, promoting its use for energy. Additionally, insulin stimulates the liver to store excess glucose in the form of glycogen, further helping to maintain balanced blood glucose levels.

While glucagon, produced by the alpha cells of the pancreas, has the opposite effect—raising blood glucose levels by promoting the release of stored glucose from the liver—insulin is the key player in lowering and maintaining glucose levels in the normal range after food intake. Cortisol and adrenaline also influence blood glucose levels but mainly during stressful situations or fasting. Cortisol increases glucose availability by promoting gluconeogenesis (the creation of glucose), while adrenaline prepares the body for the 'fight or flight' response by mobilizing energy reserves. Therefore, in the context of routine regulation of blood glucose, insulin is the main hormone involved.