Insulin pens are medical devices designed to deliver insulin conveniently and controlled, primarily for individuals with diabetes who require regular insulin therapy. They combine an insulin cartridge (pre-filled or replaceable) with a pen-like design for easier handling and dosing. These devices are a modern alternative to traditional insulin vials and syringes, simplifying the injection process and enhancing patient adherence. Insulin pens have revolutionized diabetes management by improving convenience, accuracy, and patient compliance.