Types of Insulin

Manufactured insulin comes in several types. Each type works at a different pace and most people have to use more than one kind to mimic what their bodies used to do all by themselves.

Different types of insulin are like different types of Olympic runners. Some types of insulin are like sprinters. They start quickly, get to their top speed and finish fast. Other types of insulin are like marathon runners. They start slower and they keep going slow and steady for a long time. Then there are the ones in between-not as fast as a sprint and not as slow as a marathon. No one type of insulin is better than another. All types are important to keep your child's diabetes in control.

Rapid-acting insulin, often called lispro or Humalog, is the fastest insulin of all. Once injected, it starts to work within 15 minutes. It works hardest (or "peaks") at about an hour or so after injection. It's usually used up in four or five hours. This kind of insulin is designed so it can be injected right before meals. It starts to work about the time your child starts to eat. By the time her meal is digested and sugar is beginning to move into the bloodstream, rapid-acting insulin is working the hardest at moving that sugar into the cells.

Short-acting insulin, or "regular" insulin, is also used around mealtime. It takes longer to work than rapid-acting insulin does. So your child takes short-acting insulin about 30 to 45 minutes before she plans to eat and it peaks at about two or three hours. It can keep working for as long as six hours. Rapid-acting and short-acting insulin are both "clear" insulins.

Intermediate-acting insulin, or NPH and Lente,  is insulin mixed with a substance that makes the body absorb the insulin more slowly. That's why this type of insulin looks cloudy and has to be mixed before it's injected. It takes longer to start to work, and it stays in your child's body for a longer time. NPH usually begins to work about two to four hours after injection. It peaks four to 10 hours after injection, and it keeps working for 10 to 16 hours. Lente lasts even longer. It peaks at four to 12 hours after injection and stays in the body from 12 to 18 hours. Intermediate-acting insulin works all day if it is taken in the morning. A shot of intermediate-acting insulin in the evening keeps insulin in your child's body during the night.

Long-acting insulin, also called Ultralente, starts to work in six to 10 hours and can stay in the body for 20 hours or more. It has a peak, but its top speed looks a lot like its normal speed. Long-acting insulin is usually taken in the morning or before bed, like intermediate-acting insulin.

There is also glargine (GLAR-jeen) insulin, which is very long-acting insulin. It starts to lower blood glucose levels about 1 hour after injection, and keeps working evenly for 24 hours.

Additional Information

For more information about types and particular brands of insulin, please review the Association's annual Resource Guide.