Rapid-acting insulin is a type of insulin that starts to work quickly, usually within 15 minutes after injection. It helps control blood sugar levels during meals by mimicking the natural insulin response of the body. This type of insulin is often used by people with diabetes to manage their blood glucose levels effectively. Common brands of rapid-acting insulin include Lispro, Aspart, and Glulisine. These insulins are typically taken just before or shortly after eating. Their quick action allows for more flexibility in meal timing, making it easier for individuals to maintain stable blood sugar levels throughout the day.