Humalog (insulin lispro) is a prescription drug that’s used to help treat diabetes. Humalog comes as a liquid solution for infusion or injection under the skin.
Humalog comes in two versions: Humalog and Humalog Mix. They’re part of a group of drugs called insulins. Both contain the active ingredient insulin lispro. (An active ingredient is what makes a drug work.) Humalog Mix also contains insulin lispro protamine.
Your doctor will recommend the dosage of Humalog that’s right for you. Below are commonly used dosages, but always take the dosage your doctor prescribes.
Forms and strengths
Humalog comes in two versions: Humalog and Humalog Mix. Below is information on the available forms and strengths for both versions of Humalog.
Humalog comes as a solution. Your doctor may prescribe Humalog as:
- An injection under your skin, using one of the following forms:
- the Humalog KwikPen
- the Humalog Tempo Pen
- a vial and insulin syringes
- a cartridge and reusable insulin pens
- A type of injection under your skin that’s given by an insulin pump. (An insulin pump will inject Humalog under your skin over a period of time.)
- An intravenous (IV) infusion, which is an injection into a vein that’s given over time by a healthcare professional.
Humalog contains either 100 units or 200 units of insulin lispro in each milliliter of solution. Your prescription for Humalog may state either “U-100” or “U-200” depending on which strength of the drug your doctor prescribes.
But only Humalog KwikPens come as either U-100 or U-200. Other Humalog pens, vials, and cartridges come only as U-100. (Cartridges hold insulin and are used in reusable insulin pens.)
Humalog Mix is a suspension (a type of liquid mixture) that you’ll take as an injection under your skin. You can use the Humalog Mix KwikPen to inject the drug under your skin. Or you can use the Humalog Mix vial with insulin syringes.
Humalog Mix comes in U-100 strength. It’s available as:
- Humalog Mix 50/50, which contains 50% insulin lispro and 50% insulin lispro protamine
- Humalog Mix 75/25, which contains 75% insulin lispro protamine and 25% insulin lispro
The best time to administer Humalog is either 15 minutes before you eat or right away after you’ve eaten. Your doctor will tell you how much to take for your doses.
How much Humalog you’ll take varies depending on:
- how you’ll receive Humalog
- any other medical needs you have
- your blood sugar levels
- your diabetes treatment goals
If you’re in a hospital and you need insulin, your doctor may use a dosage scale for Humalog. A dosage scale involves taking small doses of Humalog or another rapid-acting insulin as needed depending on your current blood sugar level. Your healthcare professionals will manage your insulin injections if you’re staying in a hospital.
For more information about Humalog’s recommended dosages, see this article.
How to take
Your doctor will explain how you should take Humalog. They’ll also explain how much to take and how often. Be sure to follow your doctor’s instructions.
If you’ll be receiving injections of Humalog or Humalog Mix at home, your doctor will show you or your caregiver how to give them. The prescribing information for Humalog, Humalog Mix 50/50, and Humalog Mix 75/25 also contains step-by-step instructions for giving injections of the drug.
If you’ll be receiving Humalog through an insulin pump, follow the instructions provided by your doctor or the device’s manufacturer.
If you need IV infusions of Humalog, a healthcare professional will give these infusions in a hospital setting.
Humalog sliding scale
In the past, doctors would prescribe Humalog on a sliding scale to quickly lower a person’s blood sugar level depending on their blood sugar readings. With a sliding scale, small amounts of Humalog are injected as needed based on your current blood sugar level.
Using a sliding scale requires you to test your blood sugar at home and calculate your insulin dose based on the scale. But this dosage scale is no longer recommended.
According to experts, Humalog sliding scales don’t manage blood sugar levels because they’re a reactive treatment. Sliding scales react to your current blood sugar level. But sliding scales don’t manage your insulin needs based on your past blood sugar readings.
Questions about taking Humalog
Below, we answer common questions related to taking Humalog.
- What if I miss a dose of Humalog? If you miss a dose of Humalog, take the missed dose as soon as you remember. But if it’s been longer than 1 hour since you’ve eaten, just skip the missed dose. Then, take your next dose with your following meal like usual. If you receive Humalog infusions from a healthcare professional, reschedule any missed appointments as soon as possible.
- Will I need to use Humalog long term? Diabetes, which Humalog is used to manage, is a long-term condition. So you may need to take Humalog long term if your doctor recommends it. Talk with your doctor about how long you’ll need to take this drug.
- Should I take Humalog with food? You’ll take Humalog either 15 minutes before eating or right away after eating. If you don’t eat, taking Humalog may lower your blood sugar levels to dangerously low levels.
- How long does it take for Humalog to work? Humalog and Humalog Mix work quickly to lower your blood sugar. Within 15 minutes after injection, the drugs start to lower your blood sugar levels. And after 1 hour, Humalog will have its maximum effect in your body. Humalog’s effect can last up to 4 hours. And because Humalog Mix contains a mixture of insulins, its effects can last up to 22 hours.
Don’t take more Humalog than your doctor prescribes. Using more than this can lead to serious side effects.
If you take too much Humalog, your blood sugar may drop too low, causing hypoglycemia (low blood sugar level). A severe overdose of Humalog can be life threatening.
Symptoms of severe hypoglycemia
Overdose of Humalog can cause severe hypoglycemia, which may lead to these symptoms:
What to do in case you take too much Humalog
If you have a glucagon injection available, ask someone to inject it for you, if you’re unable to do so yourself. (Glucagon will quickly raise your blood sugar level.)
Also, call your doctor if you think you’ve taken too much Humalog. You can also call 800-222-1222 to reach America’s Poison Centers or use its online resource. But if you have severe symptoms, immediately call 911 or your local emergency number. Or go to the nearest emergency room.
Note: If you haven’t already, be sure to talk with your doctor about when and how to use glucagon.
Humalog and Humulin aren’t the same drug. Humulin contains human insulin, while Humalog contains insulin lispro. And different Humulin products also contain different types of insulin.
- Humulin R contains rapid-acting human insulin that’s injected 30 minutes before eating.
- Humulin N contains a type of human insulin called isophane insulin. It’s an intermediate-acting insulin that takes longer to start working and lasts longer in your body.
Humalog also comes as Humalog Mix, which contains a mixture of rapid-acting and intermediate-acting forms of insulin lispro. Similarly, another product called Humulin 70/30 contains a mixture of rapid and intermediate-acting human insulin.
If you’d like to know more about the differences and similarities of Humalog and Humulin, see this drug article. And be sure to talk with your doctor about which drug is right for you.
Humalog is a biologic medication containing the active ingredient insulin lispro. A biologic medication is made from parts of living organisms.
The manufacturer of Humalog also makes a
In some cases, the brand-name drug and the biosimilar version may come in different forms and strengths.
Talk with your doctor if you’d like to know more about insulin lispro.
Like most drugs, Humalog may cause mild or serious side effects. The lists below describe some of the more common side effects that Humalog may cause. These lists don’t include all possible side effects.
Keep in mind that side effects of a drug can depend on:
- your age
- other health conditions you have
- other medications you may be taking
To learn more about the side effects of Humalog, see this article. Your doctor or pharmacist can also tell you more about the drug’s side effects and suggest ways to help reduce symptoms.
Mild side effects
Here’s a short list of some of the mild side effects that Humalog can cause. To learn about other mild side effects, talk with your doctor or pharmacist, or read the prescribing information for the forms of Humalog* below:
Mild side effects of Humalog that have been reported include:
- weight gain
- low blood sugar level
- lipodystrophy (changes in skin thickness near an injection site)
- mild allergic reaction†
Mild side effects of many drugs may go away within a few days or a couple of weeks. But if they become bothersome, talk with your doctor or pharmacist.
* Humalog comes in different forms and strengths. For more information, see the “What is Humalog’s dosage?” section above.
† To learn more about this side effect, see the “Allergic reaction” section below.
Serious side effects
Serious side effects from Humalog can occur, but they aren’t common. If you have serious side effects from Humalog, call your doctor right away. But if you think you’re having a medical emergency, you should call 911 or your local emergency number.
Serious side effects of Humalog that have been reported include:
- edema (swelling) in your hands and legs
- local amyloidosis, which is a buildup of amyloids (a type of protein) under your skin where you inject the drug
- allergic reaction*
* To learn more about this side effect, see the “Allergic reaction” section below.
Some people may have an allergic reaction to Humalog.
Symptoms of a mild allergic reaction can include:
- skin rash
- flushing (warmth, swelling, or redness, or discoloration in your skin)
A more severe allergic reaction is rare but possible. Symptoms of a severe allergic reaction can include swelling under your skin, typically in your eyelids, lips, hands, or feet. They can also include swelling of your tongue, mouth, or throat, which can cause trouble breathing.
Call your doctor right away if you have an allergic reaction to Humalog. But if you think you’re having a medical emergency, call 911 or your local emergency number.
Find answers to some commonly asked questions about Humalog.
How fast does Humalog work?
Humalog comes in two forms: Humalog and Humalog Mix.
The onset of Humalog’s action is 15 minutes after it’s injected. This means that the action time starts 15 minutes after you take a Humalog injection. And the drug’s action time lasts about 2 to 4 hours, with a peak effect after 1 hour. (Peak effect is when the drug has its maximum effect in your body.)
Humalog is a rapid-acting insulin, but it loses its effect quickly. This is unlike long-acting insulin, which takes longer to start working, but is longer lasting.
Humalog Mix contains a mixture of rapid-acting insulin and longer-acting insulin. Like Humalog, Humalog Mix starts working 15 minutes after it’s injected. But its effects can last up to 22 hours.
How long does Humalog last in your body?
Humalog comes in two forms: Humalog and Humalog Mix. Each form can last a different amount of time in your body.
Humalog can last about 4 to 5 hours in your body, while Humalog Mix can last about 22 hours.
Humalog’s half-life is 1 hour. This means that half of a dose of Humalog will be eliminated by your body after 1 hour. In general, after about four to five half-lives, a medication reaches very low levels and is eliminated from your body.
The half-life of Humalog Mix isn’t known for sure.
Below is important information you should consider before using Humalog.
Taking a drug with certain medications, vaccines, foods, and other things can affect how the drug works. These effects are called interactions.
Humalog can interact with several other medications.
Before taking Humalog, talk with your doctor or pharmacist. Tell them about all prescription, over-the-counter, and other drugs you take. Also, tell them about any vitamins, herbs, and supplements you use. Sharing this information can help you avoid potential interactions.
For more information about Humalog and interactions, see this in-depth article.
Below is a list of medications that can interact with Humalog. This list does not contain all drugs that may interact with Humalog. If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.
|Drug group or drug name||Drug examples|
|other diabetes drugs||• insulin glargine (Lantus)|
• insulin human (Humulin R)
• insulin NPH (Humulin N)
• glyburide (Diabeta)
• pioglitazone (Actos)
|sulfonamide antibiotics||• sulfamethoxazole/trimethoprim (Septra)|
|antidepressants||• fluoxetine (Prozac)|
• phenelzine (Nardil)
|certain high blood pressure medications||• ramipril (Altace)|
• candesartan (Atacand)
Humalog and alcohol
It is not safe to consume alcohol while taking Humalog. Alcohol can cause insulin drugs, such as Humalog, to act stronger than usual. And this can increase your risk of low blood sugar and other side effects.
Be sure to tell your doctor if you drink alcohol. Let them know how much and how often you drink. Your doctor may adjust your Humalog dosage if needed. Do not drink alcohol or take medications that contain alcohol while using Humalog before first talking with your doctor.
Pregnancy and breastfeeding
Doctors don’t have enough information on whether Humalog is harmful if used by pregnant people.
Studies show that Humalog doesn’t increase the risk of major problems with fetal development (commonly known as birth defects), pregnancy loss, or other problems during pregnancy. And there’s more risk for a pregnant person and their fetus if diabetes isn’t well-managed during pregnancy.
Currently, doctors aren’t sure whether Humalog:
- passes into human breast milk, or
- has an effect on a child who is breastfed or your body’s milk production
If you’re pregnant or breastfeeding, talk with your doctor about the benefits and risks of taking Humalog.
Humalog can sometimes cause harmful effects in people who have certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether Humalog is a good treatment option for you.
Talk with your doctor about your health history before you take Humalog. Be sure to tell them if any of the following factors apply to you:
Whether you have health insurance or not, cost may be a factor when you’re considering Humalog. What you’ll pay for Humalog may depend on several things, such as your treatment plan and the pharmacy you use.
Here are a few things to consider regarding cost:
- Cost information and savings coupons. You can visit Optum Perks* to get price estimates of what you’d pay for Humalog when using coupons from the site.
- Generic or biosimilar form. Humalog is available as the biosimilar drug insulin lispro. And Humalog Mix is available as the biosimilar drugs insulin lispro protamine and insulin lispro. Similar to generic drugs, biosimilars often cost less than brand-name drugs. (Biosimilars are like generics. But unlike generics, which are made for nonbiologic drugs, biosimilars are made for biologic drugs such as Humalog.) Talk with your doctor if you’d like to know whether insulin lispro could be an option for you.
- Savings program. If you have questions about how to pay for your prescription, talk with your doctor or pharmacist. You may also be eligible for the Lilly Insulin Value Program and other support options.
You can also check out this article to learn more about saving money on prescriptions.
* Optum Perks is a sister site of Healthline. Optum Perks coupons cannot be used with any insurance copays or benefits.
Humalog comes in two forms: Humalog and Humalog Mix. Below are the specific uses for each:
- Humalog is used in adults with type 1 or type 2 diabetes. Humalog is also used in children ages 3 years and older with type 1 diabetes. It’s not known if Humalog is safe or effective for children with type 2 diabetes.
- Humalog Mix is used in adults with type 1 or type 2 diabetes. It’s not known if Humalog Mix is safe or effective for children.
With diabetes, your body either doesn’t make enough insulin, or it doesn’t respond to insulin as it should. Insulin is a hormone that helps lower your blood sugar level. It brings sugar out of your blood and into your cells, where the sugar is used for energy. With diabetes, your blood sugar level is higher than usual.
Humalog and Humalog Mix contain a type of insulin called insulin lispro. Humalog Mix also contains a type of insulin called insulin lispro protamine. The drugs lower your blood sugar levels by:
- helping your muscle and fat cells take in sugar from your blood
- blocking your liver from making sugar
- stopping your body’s breakdown of fat and protein so that your body will use up sugar instead
You may need to take other medications together with Humalog to manage your blood sugar. If you’d like to know more about taking other drugs with Humalog, talk with your doctor.
If you have questions about taking Humalog, talk with your doctor or pharmacist. Questions you may want to ask include:
- How can I store Humalog if I am traveling to a warmer climate?
- How often do I need to check my blood sugar level while I’m taking Humalog?
- What should I do if I notice pits, thickened areas, or lumps of fat develop around my belly?
- How often do I need to change out Humalog needles?
To learn more about Humalog, see these articles:
To get information on different conditions and tips for improving your health, subscribe to any of Healthline’s newsletters. You may also want to check out the online communities at Bezzy. It’s a place where people with certain conditions can find support and connect with others.
What is the difference between Humalog KwikPen and Humalog Tempo Pen?Anonymous
Humalog KwikPens and Humalog Tempo Pens are very similar.
These pens work in the same way. But Tempo Pens can connect with a smartphone app to record your insulin doses. Humalog KwikPens don’t have this feature.
Both KwikPens and Tempo Pens hold 3 milliliters (mL) of insulin. But Tempo pens come in a strength of 100 units of insulin per mL (U-100), while KwikPens come both as U-100 and U-200, which hold 200 units of insulin per mL.
If you’d like to know more about the differences and similarities of these pens, talk with your doctor. They can recommend which device would be a better option for your needs.The Healthline Pharmacist TeamAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.
Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.