How Do Different Types of Insulin Work?

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There are many types of insulin and they are not all created equal. Each kind has its own unique action and they are not interchangeable. Which insulin is right for you? The chart below will help you understand how the various insulin medications work and why your doctor has prescribed them for you.

Insulin is injected into the fat tissue which helps it absorb into the bloodstream. Some insulin medications work faster than others, but don't last as long. And some insulins last longer but work more gradually than others.

Characteristics of Insulin Action

There are three characteristics that define types of insulin.

  1. Onset: How long it takes for the insulin to start lowering blood glucose
  2. Peak time: Time after injection when the insulin is the most effective at lowering blood glucose
  3. Duration: How long the insulin keeps lowering blood glucose

Insulin is prescribed by matching the characteristics of a particular insulin with the individual needs of the patient. Some people are on only one kind of insulin, while others take a combination of insulin medication to customize good glucose control.

Types of Insulin

There are six main types of insulin available:

  1. Rapid-acting: These include Apidra, Humalog, and Novolog. They have an onset in less than 15 minutes, peak in 30 to 90 minutes, and duration of three to five hours.
  2. Regular (short-acting): These include Humulin R and Novolin R. They have an onset of a half an hour to one hour, a peak of two to four hours, and duration of three to five hours.
  3. Intermediate-acting: These include Humulin N and Novolin N. They have an onset of one to three hours, a peak of eight hours, and duration of 12 to 16 hours.
  4. Long-acting: These include Levemir an Lantus. They have an onset of one hour, minimal or no peak, and a duration of 20 to 26 hours.
  5. Combinations/pre-mixed: These combine intermediate-acting insulins with regular insulin and are convenient for people who need to use both. These include mixtures of Humulin or Novoline, Novolog Mix, and Humalog Mix. See the chart for actions.
  6. Inhaled insulin: This became available in 2015. Afrezza has an onset of 12 to 15 minutes, a peak of 30 minutes, and duration of 180 minutes.

    Insulin Types and Actions Chart

    This chart covers the different types of insulin, how long it takes to start lowering blood sugar when the peak of action will occur, and how long it will continue to work. Be sure to read the product information provided with your medication and follow the instructions from your doctor and pharmacist for using insulin.

    Brand Name Generic Name Type Onset Peak Duration
    Apidra Insulin Glulisine Rapid Acting Less than 15 minutes 30-90 minutes 3-5 hours
    Humalog Insulin Lispro Rapid Acting Less than 15 minutes 30-90 minutes 3-5 hours
    Novolog Insulin Aspart Rapid Acting Less than 15 minutes 30-90 minutes 3-5 hours
    Humulin R Regular Regular - Short Acting 1/2 - 1 hour 2-4 hours 5-8 hours
    Novolin R Regular Regular - Short Acting 1/2 - 1 hour 2-4 hours 5-8 hours
    Humulin N NPH Intermediate Acting 1-3 hours 8 hours 12-16 hours
    Novolin N NPH Intermediate Acting 1-3 hours 8 hours 12-16 hours
    Levemir Insulin Detemir Long Acting 1 hour minimal peak action 20-26 hours
    Lantus Insulin Glargine Long Acting 1 hour no peak 20-26 hours
    Humulin or Novolin 70/30 Combination/Pre-Mixed 0.5 - 1 hour 2-10 hours 10-16 hours
    Novolog Mix 70/30 Combination/Pre-Mixed Less than 15 minutes 1-2 hours 10-16 hours
    Humalog Mix 75/25 or 50/50 Combination/Pre-Mixed Less than 15 minutes 1-2 hours 10-16 hours
    Afrezza Inhaled 12-15 minutes 30 minutes 180 minutes
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    Article Sources
    • "2007 Resource Guide." Diabetes Forecast January 2007: 13-18.
    • Insulin Action." Learn About Diabetes. 2006. Joslin Diabetes Center. 12 Dec 2006.
    • Insert C: Types of Insulin, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health.
    • Insulin Basics, American Diabetes Association, July 16, 2015.