How Do Different Types of Insulin Work?

Insulin is a hormone made by the pancreas that allows your body to use sugar (glucose) from carbohydrates in the food that you eat for energy or to store glucose for future use. Diabetes is a health condition in which the body is unable to regulate blood sugar on its own through insulin. There are two distinct types of diabetes:

Type 1 diabetes (T1D): T1D, once known as juvenile diabetes or insulin-dependent diabetes, is a chronic condition in which the pancreas produces little or no insulin. Different factors, including genetics and some viruses, may contribute to T1D.

Type 2 diabetes (T2D): T2D is a chronic condition that affects the way your body metabolizes sugar. In T2D, the body either resists the effects of insulin or doesn't produce enough insulin to maintain normal glucose levels. Genetics and environmental factors, such as being overweight and inactive, have been established as contributing factors.

All patients with T1D and patients with more serious forms of T2D need to take insulin medications to help their body regulate blood sugar.

There are many types of insulin medications available. Each kind has its own unique action and they are not interchangeable. The chart below will help you understand how the various insulin medications work and why your healthcare provider 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. Your healthcare provider will review your medical history to determine the insulin medication most appropriate for you.

Characteristics of Insulin Action

There are three characteristics that define how insulin medication function:

1. Onset: How long it takes for the insulin to start lowering blood glucose
2. Peak time: Time after administration 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 of less than 15 minutes, peak in 30 to 90 minutes, and duration of two to four hours.
2. Regular (short-acting): These include Humulin R and Novolin R. They have an onset of a half an hour, a peak of two to three hours, and duration of three to six hours.
3. Intermediate-acting: These include Humulin N and Novolin N. They have an onset of two to four hours, a peak at four to 12 hours, and duration of 12 to 18 hours.
4. Long-acting: These include Levemir, Lantus, Semglee, and Tresiba. They have an onset of several hours, minimal or no peak, and a duration of 24 hours or more. Tresiba has been shown to last up to 42 hours.
5. Ultra long-acting: These include Toujeo. They have an onset of six hours, no peak, and a duration of 36 hours.
6. 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.
7. Inhaled insulin: This became available in 2015 and is used in combination with long-acting insulin. Afrezza has an onset of 12 to 15 minutes, a peak of 30 minutes, and duration of three hours.

Insulin Types and Actions Chart

This chart covers the different brands of insulin, how long it takes for each to start lowering blood sugar, when the peak of action will occur, and how long it will continue to work. Read the product information provided with your medication and follow the instructions from your healthcare provider and pharmacist for using insulin.