Novolog and Humalog are both diabetic drugs used to control blood sugar levels in diabetic patients. They are both fast-acting drugs, meaning they work faster compared to other insulin medicines. According to the American Diabetes Association, both medications start to work after 15 minutes. However, they reach their peak after 1 hour, while their effects can be felt up to 2 to 4 hours. Both insulin drugs provide mealtime glucose control. After taking these drugs, you should eat a few minutes later to avoid the risk of having hypoglycemia. You may need to use these drugs with intermediate-acting insulin or long-acting insulin drugs to manage blood glucose levels between meals.

Humalog (Insulin Lispro)

Humalog or insulin lispro is a fast-acting insulin commonly used to treat type 1 diabetes in adults but can also be used by patients with type 2 diabetes. For insulin lispro to be most effective, you are supposed to take this drug 15 minutes before a meal or immediately after you eat. To remember your dosage, make sure you use this insulin at the same time every day. The drug is usually a part of a treatment program that includes exercise and diet. Therefore, you will need to carefully follow your medication, exercise, and diet program to avoid adverse changes in blood sugar. Insulin lispro is administered by subcutaneously injecting the insulin in the upper arm, thigh, or buttock. Your doctor may adjust your dosage based on physical activity, acute illness, or changes in eating pattern. Insulin lispro comes in 10 ml vials, 3 ml vials, 3 ml KwikPens, and 3ml cartridges. Humalog KwikPen is a pen that is lightweight and comes prefilled with insulin lispro that you can use on the go. You should not take it if you are allergic to insulin lispro or another drug ingredient.

Novolog (Insulin Aspart)

Novolog is a fast-acting mealtime insulin that helps to lower blood glucose spikes after eating. Therefore, after injecting this insulin, it begins to work immediately. Your doctor will show you the best places to inject the insulin in your body. The drug is usually injected under the skin or vein using an IV injection. If you are not sure how to use the injection, you should not use it. Your health care provider will show you how to use it at home. You are required to take a meal 5 to 10 minutes after using this drug. Insulin aspart is known to reduce high blood sugar levels in diabetic patients when taken with long-acting insulin. When this insulin is taken with long-acting insulin during mealtime, it can lower your A1C levels. As you take this medication, keep checking your blood sugar regularly and sharing the results with your doctor. This will help them determine the right insulin dose for you. To avoid the risk of infections, you should not share an injection pen, syringe, or cartridge with any other person.

Similarities and Differences between Novolog and Humalog


Both medications are human insulin analogs. That means they are an altered form of the human insulin, which is produced by the pancreas. Also, both medications are considered to be rapid-acting insulin. When you inject these insulins, you will start to feel the effect after 15 minutes and will reach their peak after 1 hour. The effects of both insulins will last between 2 to 4 hours. To reduce the risk of hypoglycemia, you are required to take a meal a few minutes after using either insulin drug. To be effective, you are required to take these medicines with long-acting insulin.

As far as cost is concerned, they both have the same price. However, since both drugs are covered by insurance providers, the amount you will pay for them will depend on your insurance provider. The drugs have no generic version. The common side effect between them is hypoglycemia. As you take these insulin drugs, make sure your blood glucose level does not go below 70 mg/dL. You can do this by testing your blood sugar regularly.

Other common side effects include the following:

  • Nausea
  • Weight gain
  • Diarrhea
  • Headaches

Serious side effects may also occur when you use both these drugs:

  • Swelling
  • Allergic reactions like wheezing, difficulty breathing, hives, itching
  • Heart disease
  • Low level of blood potassium
  • Injection site reactions like irritation, redness, and pain
  • Fluid retention


There are differences between Novolog and Humalog, meaning that the two insulin medications are not interchangeable. First of all, you need to understand that Novolog is the brand name for insulin aspart, while Humalog is the brand name for insulin lispro. Insulin is normally used by diabetic people to help them keep their blood sugar levels at a healthy level. Fast-acting insulin, such as these two insulin medications, is considered to work the same as the insulin that is produced in our bodies. Insulin lispro differs from the human insulin produced by the pancreas because proline, which is an amino acid at position B28, is replaced by lysine, while lysine at position B29 is substituted by proline. On the other hand, insulin aspart has only one changed amino acid, which is proline substituted for aspartic acid in position B28. These changes help both medicines be absorbed faster into the bloodstream. Also, peak levels are reached much faster compared to human insulin.

However, there are some differences between the two in terms of dosing. Humalog suggests that you inject the insulin lispro within 15 minutes after you eat, or immediately after you finish your meal. On the other hand, Novolog recommends that you take the injection 5 to 10 minutes before you eat or as you start taking your meal. Humalog can be used to treat patients with type 1 diabetes in both adults and children who have reached the age of 3 years. In addition, it can be used by patients with type 2 diabetes. However, Novolog is used to treat adults who have type 1 diabetes and children who have reached the age of 2 years. Novolog can also be used by adults who have type 2 diabetes. Another difference between medications is that both Novolog and Humalog can be diluted, but Humalog cannot be diluted in the actual pump. In case you need a lower Novolog dose than what you are using, you can dilute it with a Novolog diluting medium. Ask your doctor how you can do this correctly.

Disclaimer: Please note that the contents of this community article are strictly for informational purposes and should not be considered as medical advice. This article, and other community articles, are not written or reviewed for medical validity by Canadian Insulin or its staff. All views and opinions expressed by the contributing authors are not endorsed by Canadian Insulin. Always consult a medical professional for medical advice, diagnosis, and treatment.