What type of insulin is regular insulin classified as?

Regular insulin is classified as short-acting insulin because of its pharmacokinetics, which allow it to start working within 30 minutes after injection, peak at around 2 to 3 hours, and generally last for about 6 to 8 hours. This characteristic makes it suitable for managing blood glucose levels during meals when a rapid increase in insulin action is needed to counteract carbohydrate intake.

In contrast, long-acting insulins provide a steady release over an extended period, intermediate-acting insulins have a duration of action that is longer than regular insulin but shorter than long-acting forms, and rapid-acting insulins act much faster and are designed for immediate effects, typically taken just before or after meals. Thus, regular insulin’s specific action profile aligns it distinctly with the short-acting classification.