Skip to content

Insulin is a hormone that treats diabetes by controlling the amount of sugar in the blood.

There are many types of insulin used to treat diabetes. They are classified by:

  • How fast they start to work
  • When they reach their "peak" (the concentration of insulin in your blood is highest)
  • How long they last

Types of insulin include:

Rapid-acting insulin. This starts working within a few minutes and lasts for a couple of hours.

Regular- or short-acting insulin. It takes about 30 minutes to work fully and lasts for 3 to 6 hours.

Intermediate-acting insulin. This takes 2 to 4 hours to work fully. Its effects can last for up to 18 hours.

Long-acting insulin. There are no peak levels in the bloodstream, and it can keep working for an entire day.

It's possible that you may need more than one type of insulin or to take it more than once a day. You may also need to space your insulin doses throughout the day to keep your blood sugar levels stable.

Depending upon your particular needs, your doctor may prescribe other medications to take along with insulin.

How Do I Take Insulin for Diabetes?

You can give yourself an insulin injection using a needle and syringe, a cartridge system, or prefilled pen systems. Inhaled insulin, insulin pumps, and a quick-acting insulin device are also available.

If you're using an injectable insulin, the place on the body where you give yourself the shot may affect the timing of its benefit to you.

You'll absorb insulin the most consistently when you inject it into your belly. The next best places to inject your insulin are the arms, thighs, and buttocks.

You should try to consistently inject insulin at the same general area of your body. Within that general area, you should alternate the location of the exact injection spot. This helps minimize scarring under the skin.

What Are the Side Effects of Insulin?

The major side effects of insulin taken for diabetes include:

  • Low blood sugar
  • Lumps or scarring of the area of the body where you've had too many insulin injections
  • Rash at the site of injection or over the entire body (rare)
  • Weight gain when you first start using insulin
  • With inhaled insulin, there's a risk of a sudden tightening of the lungs in people who have asthma or the lung disease COPD.