The journey of insulin over 100 years

The year 2021 marks 100 years of insulin discovery. In 1921, Banting and Best identified the pancreas as a key organ mainly responsible for carbohydrate metabolism and pathogenesis of diabetes. This work led to the purification of extract from the pancreas, which was later identified to be insulin. Since its discovery, there has been a lot of work to refine the properties of insulin and improve patient outcomes. Presently, short-acting, rapid-acting, intermediate-acting, long-acting, ultra-long-acting co-formulations, biosimilar, concentrated insulins are available and have revolutionized diabetes management and patient care. These new preparations have onset of action in a few minutes and some have their action lasting around 48 h. Also, there are a lot of advances in insulin delivery devices with the availability of ultra-fine needles and prefilled, reusable pens to hybrid closed-loop systems in which insulin is delivered as per continuous glucose monitoring recordings. Our article enfolds the milestones in insulin discovery and its evolution from the crude extract to highly designed once-weekly insulin.