This graph shows an approximation of insulin response to meals in patients without diabetes. Insulin therapy is intended to mimic these responses to keep blood glucose under control.

Types of insulin available include rapid-acting, short-acting, intermediate-acting, long-acting, and pre-mixed. This graph shows the approximate action on insulin levels of several insulin medications. The bolus, or quick-acting insulin is given at mealtimes and offsets the effects of dietary carbohydrates. The basal or longer-acting insulins offset hepatic glucose secretion, meeting the body’s basic metabolic energy needs. Rapid-acting works has an onset of 10-30 minutes and peaks between 30-90 minutes. Variations are seen in duration from 1-2.5 or 3-5 hours. Short-acting, shown here as “regular”, have and onset of ½ to 1 hour, a peak of between 2-5 hours, and varied durations from 2-3 hours or 5-8 hours. Intermediate-acting insulin, such as NPH or Lente, have onsets between 1-2.5 hours, a peak between 3-12 hours, and a duration of 18-24 hours. Long-acting includes ultralente, lantus, and levemir or detemir. The onset ranges from ½ to 2 hours, peak levels are varied from 6-8 hours or 10-20 hours, except for lantus, which is delivered at a steady level. The duration ranges from 20-36 hours. This type of insulin is often combined with rapid or short-acting insulin therapy. Pre-mixed include products such as humulin, novolin, novolog, and humalog. These mixes have both a quick onset and a long duration.