Rapid-acting insulins are in a form that the body can absorb right away, without having to break it down. With regular insulin, the body needs to reduce the insulin protein chain to a smaller size before it can be absorbed and go to work. It can take over 30 minutes from the time regular insulin is injected until it starts working on cells. With rapid-acting insulins, this time is cut in half, so there’s less room for error. It goes to work almost as fast as naturally produced insulin does.
Rapid-acting insulin may give you a lot more flexibility. You can count the carbohydrates in your meal and take insulin to cover that amount. If you eat an extra helping at a meal, you can take care of the carbohydrates with a booster shot right away. You may even be able to wait until you know how much carbohydrate you’ve eaten to inject these insulins. Also, because rapid-acting insulins don’t remain in the body as long as regular insulin does, you may experience fewer episodes of hypoglycemia. Ask your provider whether you could benefit from using a rapid-acting insulin.