Insulin is a vital hormone produced by the beta cells of the pancreas that regulates blood glucose levels by allowing glucose to enter body cells for energy and storage, while also supporting fat metabolism and protein synthesis; a deficiency of insulin leads to diabetes mellitus, a condition that was once fatal before its discovery. In 1921, Frederick Banting and Charles Best successfully isolated insulin at the University of Toronto under the supervision of John Macleod, with purification by James Collip, and in 1922 it was first administered to a 14-year-old boy with type 1 diabetes, producing dramatic improvement and transforming diabetes into a manageable disease; they were awarded the Nobel Prize in 1923, and since then insulin production has evolved from animal sources to recombinant DNA technology, leading to modern synthetic human insulin and analogs used worldwide today.
