Insulin is a crucial compound for the management of diabetes, both type 1 and type 2; however, it is more commonly used for the management of type 2 diabetes. Insulin pen device is a fairly new innovation and was first introduced over 20 years ago. It has evolved to offer significant advantages as compared to the vial and syringe. The pens come in two forms – disposable and reusable. Disposable insulin pens contain a prefilled cartridge.