Insulin Lispro Injection

Insulin lispro injection is a human-made form of insulin. It helps adults and children with diabetes maintain healthy blood sugar levels. Lispro is taken with meals and starts working within minutes.

What is insulin?

Insulin is a hormone. It helps your body maintain healthy blood sugar levels by:

  • Converting sugars from food (glucose) into energy.
  • Storing excess glucose in the liver when necessary.


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What is insulin lispro injection?

Lispro is human-made insulin. It is a fast-acting insulin analog, meaning:

  • It’s like insulin.
  • The effects take place within a few minutes.

The drug has many brand names, including:

  • Admelog®.
  • Humalog®.

What does lispro insulin treat?

You may need this drug if you have diabetes. There are two main types:

  • Type 1 often starts in childhood. It occurs when autoimmune disease destroys your body’s ability to produce insulin.
  • Type 2 develops over time and can be related to unhealthy eating or having overweight/obesity. It takes more insulin than usual to maintain normal blood sugar levels.


How does it work?

Under normal circumstances, eating triggers a spike in insulin levels. This prepares the body for the surge of glucose that occurs after digestion starts. If you have diabetes, the insulin spike does not occur or is not strong enough to be effective. Insulin lispro works quickly to raise insulin levels.

Will I still need to take other insulin injections?

People with Type 1 diabetes usually need two types of insulin, long-acting insulin and short- or fast-acting insulin. People with Type 2 diabetes may take pills, non-insulin injectables or insulin.

This is because insulins work in different ways:

  • Rapid-acting insulin analog starts working within minutes. It's only effective for a few hours.
  • Regular-acting insulin starts working within 30 minutes and is effective for several hours.
  • Long-acting insulin can take a few hours to start working. But it remains effective for hours longer (often 24 hours or longer).


What should I tell my healthcare provider before taking this medicine?

It’s important to share whether you are pregnant, trying to get pregnant or breastfeeding.

They also need to know if you have:

How should I use this medicine?

Your healthcare provider will prescribe the dose that’s appropriate for your needs.

Here’s how to give yourself an injection:

  • Pick up insulin vials, cartridges or dosing pens at your local pharmacy.
  • If you use a pen, attach a needle to the tip of it.
  • Take the cap off the needle tip of the pen or syringe.
  • Prime the insulin pen before each use.
  • Inject insulin lispro five to 15 minutes before your meal.
  • Have food ready before injection.
  • Do not delay eating.

What are the benefits of using rapid-acting insulin?

The main benefit is that your body maintains appropriate blood glucose levels. This may help you avoid complications of diabetes, which include:

What side effects does insulin lispro have?

When you start using insulin lispro injections, you may experience side effects. They may also occur if your healthcare provider increases the dose.

Side effects of lispro insulin include:

  • Blurry vision or other problems.
  • Pain or burning sensation.
  • Numbness or weakness in your extremities.

What if I forget to inject insulin lispro before a meal?

If you miss a dose:

  • You can inject a missed dose right away if you remember shortly after a meal.
  • If you remember after more time has passed, follow your healthcare provider’s instructions. Or call them if you are not sure what to do.
  • Do not double up before your next meal to make up for missed doses.

Is it possible to overdose on lispro insulin?

Yes. Taking too much short-acting insulin can cause low blood sugar. You may be able to treat it on your own by eating or drinking something sugary. This will help you get relief from symptoms that may include:

Signs of a severe overdose need immediate medical care and include:

  • Difficulty breathing.
  • Fainting (syncope).
  • Seizure.

What else is important to know about lispro?

To lower the risk of complications, you should:

  • Look at the injection pen to confirm it belongs to you and has the correct dose.
  • Make sure the insulin is clear, like water, before taking it.
  • Choose an injection site that’s at least a half-inch away from your last injection.
  • Put used needles in a sharps container, not a trash can.

A note from Cleveland Clinic

Lispro insulin is a short-acting insulin that you take before meals. Your healthcare provider will prescribe the appropriate dose. They’ll also explain when and how to use it. It’s important to take the correct dose at the appropriate time. Missing a dose or taking too much at once can cause complications. If you have questions about your prescription, call your healthcare provider.

Care at Cleveland Clinic
Medically Reviewed

Last reviewed on 04/04/2022.

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