If you have diabetes, your doctor may prescribe Humalog.

It’s used to help manage blood sugar levels in adults and some children. And it can be given to people with either type 1 or type 2 diabetes.

Humalog basics

Humalog and Humalog Mix are the two forms of Humalog.

Humalog is a solution that can be given.

Humalog Mix is a liquid suspension that you can inject under your skin.

Humalog and Humalog Mix aren’t regular insulins.* Instead, they’re rapid-acting insulins. This type of insulin starts to work 15 minutes after it’s injected. And the insulin’s effect in your body lasts between 2 and 4 hours. Humalog Mix also contains a longer-acting insulin that lasts up to 22 hours.

Humalog and Humalog Mix are biologic medications that contain insulin lispro. Humalog Mix also contains insulin lispro protamine. The manufacturer of these drugs also makes insulin lispro and insulin lispro protamine available as biosimilars. (A biologic drug is made from parts of living cells. Biosimilars are like generic drugs. But unlike generics, which are made for nonbiologic drugs, biosimilars are made for biologic drugs.)

In this article we discuss how to take Humalog and Humalog Mix.

Regularinsulin is short-acting. It works within 30 to 60 minutes.

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. Below are commonly used dosages, but always take the dosage your doctor prescribes.

Taking Humalog

Humalog and Humalog Mix are the two forms of Humalog.


Humalog is a solution. Humalog may be prescribed by your doctor.

  • An injection under your skin, using one of the following forms:
    • The Humalog pen.
    • The Humalog pen.
    • A pen made of a cartridge and a pen made of a disposable pen.
  • 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 your doctor or another healthcare professional.

Humalog contains either 100 units or 200 units of the drug. Your doctor may prescribe either U-100 or U-200 for Humalog, depending on the strength of the drug.

Humalog KwikPens are either U-100 or U-200. Humalog pens, vials, and cartridges are only available in U-100. Cartridges are used in disposable pens.

Humalog Mix

Humalog Mix is a suspension that you can take under your skin. You can use the Humalog mix to inject the drug. You can use the Humalog mix with the needles.

Humalog Mix is U-100 strength. It is available as:

  • Humalog mix contains 50% of the two drugs.
  • Humalog mix 75/25 contains 75% and 25% of the drug lispro.


Humalog can be administered 15 minutes before you eat or immediately after you have eaten. Your doctor will tell you how much to take.

How much Humalog you take depends on the situation.

If you are in a hospital and need to use Humalog, your doctor may use a scale. A scale is used to determine the amount of Humalog or another rapid-actinginsulin you need to take. If you are in a hospital, your healthcare professionals will be able to manage your injections.

Humalog sliding scale

“Doctors used to prescribe Humalog on a sliding scale to quickly lower a person’s blood sugar level. The amount of Humalog injected depends on your current blood sugar level.”

You have to test your blood sugar at home and use a scale to calculate your dose of insulin. The scale is no longer recommended.

“Humalog sliding scales don’t control blood sugar levels because they are a reactive treatment Scales show your current blood sugar level. The sliding scales don’t manage your blood sugar readings.”

Taking Humalog with other drugs

Humalog may be needed to manage your blood sugar levels.

If you’re taking insulin such as Humalog, your doctor may decrease the dosage of, or have you stop taking, other diabetes drugs that increase your insulin level. Doing so helps prevent your blood sugar levels from dropping too low.

Humalog may be used with other diabetes medications.

  • metformin (Glucophage)
  • glyburide is a drug.
  • Repaglinide is a drug.
  • Aose.
  • pioglitazone (Actos)
  • liraglutide (Victoza)
  • sitagliptin (Januvia)
  • Onglyza is the name of saxagliptin.
  • canagliflozin (Invokana)
  • Humalog is not the only product that includesinsulin products.

If you want to know more about Humalog, you should talk to your doctor.

Questions about taking Humalog

We answer questions related to 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. Your body will start to lower your blood sugar naturally after you eat. So, injecting Humalog more than 1 hour after eating may cause your blood sugar to drop to unsafe levels. 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.

Questions for your doctor

You may have questions about Humalog. Discuss your concerns with your doctor.

Here are a few tips that might help you.

  • Before your appointment, write down questions like:
    • How will Humalog affect my body?
  • Bring someone with you to your appointment to make you feel more comfortable.
  • “If you don’t understand something, ask your doctor to explain it.”

“Your doctor and other healthcare professionals are available to help you. They want you to get the best care possible. Don’t be afraid to ask questions or give feedback on your treatment”

Humalog and Novolog are both used to manage blood sugar levels in people with diabetes. Novolog contains insulin aspart, while Humalog contains insulin lispro.

Both Humalog and Novolog are rapid-acting insulins, which means they work quickly after they’re injected. But these drugs can’t be substituted for one another.

Novolog can be used in adults and children. Humalog can only be used in adults and children.

For a detailed comparison of these two drugs, see our “Humalog vs. Novolog: Important Differences and More” article. And talk with your doctor if you have more questions about these medications.

Humalog and Humulin are not the same drug. Humalog and humulin contain human hormones. Different Humulin products have different types ofinsulin.

For example:

  • Humaninsulin is injected 30 minutes before eating.
  • There is a type of humaninsulin called isophane in humulin-N. It takes longer to start working and last longer in your body.

Humalog Mix is a mixture of rapid-acting and intermediate-acting forms of the drug. The product called Humulin 70/30 contains a mixture of rapid and intermediate-acting humaninsulin.

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 biosimilar form of the drug called insulin lispro. (Biosimilars are like generic drugs. But unlike generics, which are made for nonbiologic drugs, biosimilars are made for biologic drugs.)

The brand-name drug and the biosimilar version may have different strengths and forms.

If you want to know more about the drug, you should talk to your doctor.

Humalog may cause mild or serious side effects. Some of the more common side effects of Humalog are described in the lists below. All possible side effects are not included in these lists.

Side effects of a drug can depend on other factors.

  • Your age.
  • You have other health conditions.
  • You may be taking other drugs.

“The doctor or the pharmacy can tell you more about Humalog’s side effects. They can suggest ways to reduce side effects.”

Mild side effects

There are some mild side effects that Humalog can cause. You can learn about other mild side effects by talking to your doctor or a pharmacy.

There are some mild side effects of Humalog that have been reported.

Many drugs can have mild side effects that go away in a few days or weeks. If they become intolerable, talk to your doctor or pharmacist.

Humalog has different forms and strengths. The “How is Humalog taken?” section gives more information.

Serious side effects

Humalog can cause serious side effects, but they are not common. If you have serious side effects, call your doctor. If you think you have a medical emergency, you should call the emergency number.

There have been serious side effects of Humalog.

The side effect focus section gives more information on this side effect.

Side effect focus

Some of the side effects Humalog may cause are discussed.

Weight gain

You can gain weight while you’re taking Humalog, or any other insulin product.

Experts say that this happens because with treatment of high blood sugar levels, you’re no longer urinating as often or as much as before. And insulins are used to manage high blood sugar levels.

“Your body’s cells absorb sugar from your bloodstream. Your body makes fat when it absorbs too much sugar. This could lead to weight gain.”

What can help?

If you gain or lose weight, your dose ofinsulin may need to be adjusted. If you have concerns about your weight and Humalog, talk to your doctor.

If you’re gaining weight with Humalog, ask your doctor about ways to manage your nutrition and level of physical activity. Your doctor can help you develop a plan to manage your weight. Additionally, a nutritionist may be able to help you plan meals that are beneficial for people with diabetes. And an exercise specialist can suggest ways to add physical activity into your lifestyle.

Low blood sugar level

If you have a low blood sugar level, which is also called hypoglycemia, you shouldn’t take Humalog. This is because the drug will lower your blood sugar even more.

Usually, hypoglycemia occurs when your blood sugar level is below 70 milligrams/deciliter (mg/dL). The normal range for fasting blood sugar level in people with diabetes is 80 mg/dL to 130 mg/dL.

Low blood sugar can cause symptoms.

  • Or is it anxiety?
  • sweating or having chills.
  • Irritated, impatience, or confusion.
  • fast heart rate
  • dizziness
  • The skin looks pale.
  • It is blurred or impaired.
  • There is a throbbing head.

What can help?

When injecting Humalog, you should be aware of the low blood sugar levels. Check your blood sugar levels according to your doctor.

To prevent low blood sugar, you should take Humalog.

If you have low blood sugar with Humalog, you should consume something with sugar that can be quickly absorbed by your body. Such items are included.

  • Sugar tablets or gels.
  • 4 ounces of juice or regular soda is not sugar-free or diet versions.
  • A small amount of sugar, honey, or corn syrup.
  • Hard candy, gumdrops, and jellybeans.

“15 grams of sugar is all you need to raise your blood sugar level. If your blood sugar hasn’t increased after 15 minutes, you should consume another 15 g of sugar.”


It is possible to have lipodystrophy while using Humalog. The way fat tissue is distributed in your body is affected by this condition. It can happen when you inject Humalog.

You may have pitting or thickened areas on your skin.

What can help?

Humalog can be injected under the skin of your stomach, thigh, arm, or buttocks. You need to change your injection site every time you inject the drug. You will not inject into the exact same spot for each injection.

You should not inject areas of your body that have changed their fat distribution. These areas may look different. Humalog should not be injected where your skin is damaged or tender.

Allergic reaction

Some people may have an allergic reaction to Humalog.

A mild allergic reaction can include some symptoms.

  • There is a skin rash.
  • It is itchy.
  • flushing (warmth, swelling, or redness, or discoloration in your skin)

A more severe allergic reaction is not uncommon. A severe allergic reaction can cause swelling under your skin, which can be seen in your eyes, lips, hands, and feet. They can include swelling of your mouth, throat, and tongue, which can cause trouble breathing.

If you have an allergic reaction to Humalog, call your doctor. If you think you have a medical emergency, call the emergency number.

Find answers to questions about Humalog.

What’s the difference between Humalog and Admelog?

Like Humalog, Admelog is a rapid-acting insulin that’s used to manage blood sugar levels in people with diabetes. (Rapid-acting insulin works 15 minutes after it’s injected.)

Like Humalog, Admelog is taken by injection under your skin or injection into your vein. Additionally, both of these medications can be taken as an injection through an insulin pump. (Insulin pumps continuously deliver insulin into your body.)

Admelog is used in adults and some children with type 1 or type 2 diabetes, just like Humalog is. And Admelog contains the same active ingredient as Humalog: insulin lispro. But Humalog and Admelog can’t be substituted for each other.

Humalog is a follow-on version of Admelog. This means that it was developed by a different drug company.

If you have more questions, talk to your doctor. They can tell you which medication is best for you.

How fast does Humalog work?

Humalog and Humalog Mix are the two forms of Humalog.

“Humalog’s action is 15 minutes after it’s injected. The action time starts after you take a Humalog injection. The drug lasts about 2 to 4 hours, with a peak effect after an hour. Peak effect is when the drug has the most effect in your body.”

Humalog is a rapid-acting drug. This is unlike long-actinginsulin, which takes longer to start working.

Humalog mix contains both rapid-acting and longer-actinginsulin. Humalog Mix starts working 15 minutes after it is injected. Its effects can last up to 22 hours.

How long does Humalog last in your body?

Humalog and Humalog Mix are the two forms of Humalog. Each form can last a different amount of time in your body.

Humalog can last up to 5 hours in your body, while Humalog Mix can last 22 hours.

Humalog has a half-life of 1 hour. Half of Humalog will be eliminated by your body after an hour. After about four to five half-lives, a medication can reach very low levels and be eliminated from your body.

Humalog Mix is not known for its half-life.

Does Humalog need to be refrigerated?

Humalog and Humalog Mix need to be refrigerated until you are ready to use them. You should put Humalog or Humalog Mix into your refrigerator after you get it from your pharmacy. Make sure the temperature is between 36F and 46F.

Humalog or Humalog Mix can be kept at room temperature, but below 86F (30C). Within 28 days, you have to use Humalog. You have to use Humalog Mix within 28 days or the prefilled pens within 10 days.

Humalog vials, prefilled pens, and cartridges should be thrown out after 28 days if kept at room temperature. If kept at room temperature, Humalog Mix prefilled pens should be discarded after 10 days.

When considering Humalog, it is important to discuss it with your doctor.

  • Your overall health.
  • You may have medical conditions.

If you are taking any medications, tell your doctor. Some drugs can interfere with Humalog.

These and other considerations are described in detail.


Taking a drug can affect how it works. These effects are called interactions.

Before taking Humalog, you should tell your doctor about all your medications. You should also describe any vitamins, herbs, or supplements you use. Your doctor or pharmacist can tell you about any interactions that may occur.

Interactions with drugs or supplements

Humalog can interact with a lot of drugs.

Some drugs that may interact with Humalog are not on this list. Your doctor or pharmacist can tell you more about the interactions that may occur with Humalog.


If you have certain medical conditions or other factors that affect your health, Humalog may not be suitable for you. Before you take Humalog, talk to your doctor about your health history. The factors to consider are listed below.

  • Hypoglycemia. Low blood sugar (hypoglycemia) can be life threatening. Your doctor may suggest increasing how often you check your blood sugar levels when you first start Humalog or whenever your dosage is changed. During these times, you have a higher risk for hypoglycemia with Humalog.
  • Allergic reaction. If you’ve had an allergic reaction to Humalog or any of its ingredients, you shouldn’t take Humalog. Ask your doctor what other medications are better options for you.
  • Low blood potassium levels. If you have low potassium levels in your blood, taking Humalog may be dangerous. If you develop low potassium levels during treatment with Humalog, your doctor may tell you to stop taking the drug. Your doctor may also have you take supplements to raise your potassium levels.

Use with alcohol

“Alcohol can affect Humalog’s effect on blood sugar.”

Alcohol can cause Humalog to act stronger than usual. This can increase your risk for low blood sugar.

“If you drink alcohol, tell your doctor. Let them know how much you drink. If you need it, your doctor may adjust your Humalog dosage. Before talking with your doctor, don’t drink alcohol or take medications that contain alcohol.”

Pregnancy and breastfeeding

There is not enough information on whether Humalog is harmful to 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.

Doctors are unsure whether Humalog is.

  • It can be passed into human breast milk.
  • “It affects a child who is breastfed or your body’s milk production.”

If you are pregnant or breastfeeding, you should talk to your doctor about the risks and benefits of Humalog.

There are many factors that affect the cost of prescription drugs. What your insurance plan covers is one of the factors.

The active ingredient in Humalog, insulin lispro, is available in biosimilar form. And the manufacturer has also made the active ingredients in Humalog Mix available in biosimilar form. These are called insulin lispro and insulin lispro protamine.

Similar to generics, biosimilars often cost less than brand-name drugs. (Biosimilars are like generic drugs. But unlike generics, which are made for nonbiologic drugs, biosimilars are made for biologic drugs such as Humalog.)

If you have questions about how to pay for your prescription, talk with your doctor or pharmacist. You can also visit the Humalog manufacturer’s website to see if it has support options.

If you have diabetes, your doctor may prescribe Humalog.

The drug works to help manage blood sugar levels in people with either type 1 or type 2 diabetes.

Humalog and Humalog Mix are the two forms of Humalog. Below are the specific uses for each:

  • Humalog is used in people with diabetes. Humalog is used in children with type 1 diabetes. Humalog is not known if it is safe for children with type 2 diabetes.
  • Humalog mix is used in people with diabetes. Humalog Mix is not known if it is safe for children.

With diabetes, your body either doesn’t make enough insulin, or it doesn’t respond to insulin normally. 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. So, with diabetes, your blood sugar level is higher than normal.

Humalog and Humalog mix contain a type ofinsulin lispro. Humalog mix also contains a type of diabetes medication. The drugs lower your blood sugar levels.

  • Your fat cells and muscle take in sugar from your blood.
  • blocking your body from making sugar
  • Your body will use up sugar if you stop it from breakdown.

“Don’t take more Humalog than your doctor prescribes. Side effects can be serious if you use more than this.”

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 cause your blood sugar to drop very low, which can be life threatening.

Symptoms of severe hypoglycemia

Severe hypoglycemic symptoms can be caused by overdose of Humalog.

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 the American Association of Poison Control 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.

Talk to your doctor or pharmacist if you have questions about Humalog. Your doctor can tell you about other treatments. There are some articles that you might find useful.

Some questions to ask your doctor about Humalog.

  • How can I keep Humalog when I travel to a warmer climate?
  • How often do I need to check my blood sugar level?
  • What should I do if I notice fat around my belly?
  • How often do I need to change Humalog needles?

You can learn more about the uses of Humalog by subscribing to Healthline’s type 2 diabetes newsletter. You can also read advice and stories from others with your condition in the Bezzy T2D community.


What is the difference between Humalog KwikPen and Humalog Tempo Pen?



Humalog pens and Humalog pens are very similar.

The pens work the same way. You can record your blood sugar levels with the app on your phone. Humalog KwikPens do not have this feature.

3 liters of insulin can be held by both the KwikPens and Tempo Pens. The U-100 and U-200 pens have 200 units ofinsulin per mL, while the U-100 and U-200 pens have 100 units ofinsulin per mL.

If you want to know more about the differences and similarities of these pens, you should talk to your doctor. They can recommend a better device for you.

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.