Skip to main content

What type of insulin is Humalog?

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on May 2, 2023.

Official answer


Humalog (insulin lispro) is a fast-acting insulin. It begins working to lower blood sugar levels about 15 minutes after injection, reaches a peak in about 1 hour, and continues to work for 2 to 4 hours. Humalog helps to control the blood sugar spikes that may occur during mealtime. It is taken within 15 minutes before eating or right after eating a meal.

Humalog (insulin lispro) is given by a subcutaneous (under the skin) injection and should generally be used in regimens with an intermediate- or long-acting insulin. Longer-acting insulins are also used to help to control blood sugar levels in-between meals and at night.

Humalog may also be given by subcutaneous infusion using an external insulin pump or given as an intravenous infusion after dilution and under medical supervision.

In general, insulin is a hormone that works by lowering levels of glucose (sugar) in the blood in patients with type 1 diabetes and type 2 diabetes. There are different types of insulin to help cover the mealtime and day-long needs for blood sugar control.

Always follow your healthcare provider’s instructions on when and how often you should check your blood sugar levels.

What are the types of insulins?

These terms are used to describe how an insulin works:

  • The onset of an insulin is how soon the insulin starts working.
  • The insulin peak is when it is working most effectively and levels are their highest.
  • The duration of insulin is how long the insulin lasts in the body.

Insulin is classified according to how quickly and how long it works in the body to control blood sugar levels:

  • Fast-acting insulin: onset usually 15 to 30 minutes, with a peak at 30 minutes to 2 hours, and a duration up to 2 to 4 hours. Fast-acting insulin is used to lower blood sugar levels after meals. Examples include Humalog, Apidra, and Novolog.
  • Short-acting (regular) insulin: onset is usually 30 minutes to one hour, with a peak at 2 to 3 hours, and a duration up to 3 to 6 hours. Short-acting insulin can cover insulin needs for meals eaten within 30 minutes after injection. Examples include Humulin R and Novolin R.
  • Intermediate-acting insulin: onset is usually in 2 to 4 hours, with a peak at 4 to 12 hours, and a duration up to 12 to 18 hours. This type of insulin can cover your insulin needs between meals and during the night. Examples include Humulin N and Novolin N.
  • Long-acting insulin: onset usually in 1 to 4 hours, with little to no peak, and a duration up to 24 hours or longer. Long-acting insulins manage blood sugar levels at night and between meals. Examples include Basaglar, Lantus, Levemir, Toujeo and Tresiba.

Humalog is manufactured by Eli Lilly.

Learn more: What is the difference between Admelog and Humalog?

This is not all the information you need to know about Humalog for safe and effective use and does not take the place of talking to your doctor about your treatment. Review the full Humalog information here, and discuss any questions you have with your doctor or other health care provider.

Related Questions


Read next

Related medical questions

Drug information

Related support groups