Humalog vs. Novolog: Important Differences and More

Humalog vs. Novolog: Important Differences & More


Humalog and Novolog are two diabetes medications. Humalog is the brand-name version of insulin lispro, and Novolog is the brand-name version of insulin aspart. These drugs both help control blood glucose (sugar) in people with type 1 and type 2 diabetes.

Humalog and Novolog are rapid acting. That means they work more quickly than other types of insulin. There are important distinctions between Humalog and Novolog, however. Check out this comparison so you can work with your doctor to choose a drug that’s right for you.

Understanding insulin

Insulin is injected under your skin fat. It’s the most common type of treatment for type 1 diabetes because it works quickly. It’s also the only type of diabetes medication that’s absorbed into the bloodstream. Humalog and Novolog are both equivalent to the insulin made in your body. Unlike oral diabetes drugs, insulin provides fast relief for changes in your blood sugar. The type of insulin your doctor prescribes depends on how often and how much your blood sugar fluctuates each day.

Drug comparison at a glance

The table below provides quick facts at a glance.

Brand name HumalogNovolog
What is the generic drug?insulin lisproinsulin aspart
Is a generic version available?nono
What does it treat?type 1 and type 2 diabetestype 1 and type 2 diabetes
What form does it come in?solution for injectionsolution for injection
What strengths does it come in? • 3-mL cartridges
• 3-mL prefilled KwikPen
• 3-mL vials
• 10-mL vials
• 3-mL FlexPen
• 3-mL FlexTouch
• 3-mL PenFill cartridges
• 10-mL vials
What is the typical length of treatment?long-termlong-term
How do I store it?Refrigerate at 36° to 46°F (2° to 8°C). Do not freeze the drug. Refrigerate at 36° to 46°F (2° to 8°C). Do not freeze the drug.

About rapid-acting insulins

Humalog and Novolog are in the rapid-acting class of insulin. Rapid-acting insulin works more quickly than other types of insulin. The American Diabetes Association estimates that both medications start working after 15 minutes. Humalog and Novolog last two to four hours and reach their peak after one hour. The exact time frame of the onset, peak, and duration may vary slightly for you. That’s why it’s important to check your blood sugar levels before and after taking Humalog or Novolog. Also, you must eat within a short time after using either drug. Delaying eating after using a rapid-acting insulin could cause hypoglycemia (low blood sugar).

If your doctor prescribes you Humalog or Novolog, you’ll likely need a long-acting insulin as well. Your doctor will decide your dosage.

Read more: Diabetes Mine: Perspectives on test driving insulin »

Drug feature differences

Both Humalog and Novolog help lower and stabilize your blood sugar when used as prescribed. But there are a few differences between the drugs. For example, there are differences in who can take the drugs, when you can take them, and the dosage.

Novolog can be used by adults and children at least 2 years old who have type 1 or type 2 diabetes. Adults and most children with type 1 diabetes can use Humalog, but the drug hasn’t been studied in children younger than 3 years. Adults with type 2 diabetes are sometimes prescribed Humalog, too.

For the best results, you should use Humalog 15 minutes before eating. If that’s not possible, take it right after the meal.

Novolog takes action in the body more quickly than Humalog, so you can take it closer to a meal. The best results are achieved if you take Novolog five to 10 minutes before eating.

Another difference is that only Novolog can be diluted. If you need a dose lower than the amount you have, you can dilute Novolog with Novolog diluting medium. Ask your doctor about the correct way to do this.

Cost, availability, and insurance

Both Humalog and Novolog are only available as brand-name medications and have no generic versions. The drugs cost about the same. However, the amount you pay depends on your health insurance coverage. Both medications are usually covered by health insurance companies and are available at most pharmacies.

Side effects

Low blood sugar is the most common side effect of Humalog or Novolog. While it’s important to lower your blood sugar levels if you have diabetes, it is possible for your blood sugar level to get too low. You should be sure your blood sugar level does not fall below 70 mg/dL. Sometimes dangerously low blood sugar can occur when taking insulin. Other factors can affect your blood sugar level, as well. These include your diet, exercise habits, and stress levels. This is why testing your blood sugar as often as your doctor says to is so important.

Other common side effects of Humalog and Novolog include:

  • diarrhea
  • headaches
  • nausea
  • weight gain

Serious side effects can also occur. These can include:

  • reaction at the injection site
  • fluid retention and swelling
  • heart disease
  • low blood potassium levels
  • allergic reactions such as hives, itchiness, breathing trouble, wheezing, or swelling in your face


Other medications may interact with Humalog and Novolog. These interactions can cause side effects in your body. For instance, some interactions may cause your blood sugar level to drop dangerously low. Other interactions may make Humalog or Novolog less effective. In other words, the drugs won’t work as well as they should to treat your diabetes.

Both Humalog and Novolog interact with the following drugs:

  • high blood pressure drugs, including beta blockers
  • androgens (male hormones)
  • alcohol

Make sure you tell your doctor about all prescription and over-the-counter drugs, supplements, and herbs you’re taking. This information can help them prevent drug interactions.

You should also tell your doctor about all health conditions you have. Certain medical conditions, such as liver, kidney, and heart disease, may change the way insulin works in your body.

Talk with your doctor

Rapid-acting insulins like Humalog and Novolog are most often prescribed for people who have big swings in their blood sugar throughout the day. Both of these drugs work in similar ways to give your body insulin quickly. Your doctor can help you decide the best type of rapid-acting insulin for your diabetes.

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