Which hormone regulates blood sugar levels by lowering it?

Which hormone regulates blood sugar levels by lowering it? The answer is insulin. Insulin is a peptide hormone made by beta cells in the islets of Langerhans, clusters of endocrine cells in the pancreas. After a meal, rising blood glucose stimulates insulin release.

Insulin lowers blood glucose by helping muscle and fat cells take up glucose from the bloodstream. It also encourages the liver and muscles to store glucose as glycogen and reduces the liver’s production of new glucose. Together, these actions help keep blood sugar within a controlled range.

Insulin was first isolated and used therapeutically in the early 1920s by researchers including Frederick Banting, Charles Best, James Collip, and John Macleod. In type 1 diabetes, the body produces little or no insulin because pancreatic beta cells are destroyed, so insulin replacement is essential. Type 2 diabetes usually involves insulin resistance, sometimes followed by insufficient insulin production. A common mix-up is glucagon: it generally raises blood glucose, making it insulin’s functional counter-regulator.