Which type of insulin typically acts quickly after administration?

Fast-acting insulin is designed to quickly lower blood glucose levels following meals. It begins to take effect within about 15 minutes of administration, peaks in about 1 to 2 hours, and has a duration of action lasting approximately 3 to 5 hours. This rapid onset makes it particularly useful for managing postprandial blood glucose spikes, allowing individuals with diabetes to better control their glucose levels in response to food intake.

The other types of insulin listed have different action profiles. Long-acting insulin provides a slow and sustained release of insulin, which helps to maintain baseline insulin levels over a longer duration. Intermediate-acting insulin has a longer onset compared to fast-acting types and is often used for a more gradual increase in insulin levels. Slow-acting insulin is similar in concept to long-acting insulin, emphasizing a prolonged release but may not be commonly referred to in this specific way in clinical settings.