This review compares insulin glargine (IGlar) and the new insulin analog LY IGlar in diabetes treatment. IGlar, a long-acting insulin analog, has been widely used clinically. Insulin glargine LY29630160 (LY IGlar) has a special chemical structure with potential advantages like a longer half-life and improved absorption. Clinical studies show comparable blood sugar control efficacy between the two, with LY IGlar having a potentially lower hypoglycemia risk. They have similar effects on blood glucose regulation and other side effects. Dosing differences of LY IGlar may simplify regimens, and patient feedback varies. Future research needs larger and longer studies to address limitations and explore combination therapies and cost-effectiveness.