The insulin delivery sub‑segment dominates the diabetes therapy drug delivery segmentation, accounting for roughly 55 % of total market volume. Insulin remains the cornerstone of glycemic control for both Type 1 and advanced Type 2 patients, driving demand for multiple delivery formats such as pre‑filled pens, disposable cartridges, and implantable pumps. Each format contributes distinct cost structures and patient adherence profiles, which are reflected in market sizing models. Pen devices, for example, capture the bulk of the segment due to their balance of dosing accuracy and user convenience, while pump systems, although representing a smaller share, command higher per‑unit revenue because of advanced telemetry and closed‑loop capabilities. The analytical breakdown also considers regional prevalence of Type 1 diabetes, reimbursement policies, and the aging demographic that influences the shift toward user‑friendly devices. Consequently, insulin delivery’s share is a function of clinical necessity, technology diffusion, and health‑system economics, reinforcing its pivotal role in the overall market.