Lispro is a rapid-acting insulin used to help control blood sugar levels in people with diabetes. It works quickly after injection, usually within 15 minutes, and its effects can last for about 2 to 4 hours. This makes it particularly useful for managing blood sugar spikes that occur after meals. Patients typically take Lispro just before or shortly after eating. It is often prescribed alongside long-acting insulins to provide a comprehensive approach to blood sugar management. Like all insulins, it is important for users to monitor their blood sugar levels regularly to avoid potential complications.