Humalog (insulin lispro)

Medically Reviewed By Victor Nguyen, PharmD, MBA

About Humalog

Humalog and Humalog Mix are brand-name prescription medications approved by the Food and Drug Administration (FDA). They help manage blood sugar levels in people with the conditions shown in the table below.

Use in Condition treated Medication
adults type 1 diabetes
type 2 diabetes
Humalog or Humalog Mix
children ages 3 years and older • type 1 diabetes Humalog

Throughout this article, the term “Humalog” is often used to describe both Humalog and Humalog Mix.*

Humalog Mix has a limitation of use. For details about this and diabetes, see the “Humalog: Uses” section below.

* Humalog and Humalog Mix are available in several strengths and forms. These include Humalog U-100, Humalog U-200, Humalog Mix 75/25, and Humalog Mix 50/50. For details, see the “Humalog: Dosage” section below.

Key points

The following table provides key facts about Humalog.

Active drugs • Humalog: insulin lispro
• Humalog Mix: insulin lispro and insulin lispro protamine
Drug class • rapid-acting insulin
Forms • Humalog: solution that’s given by subcutaneous injection or IV infusion
• Humalog Mix: liquid suspension that’s given by subcutaneous injection

Finding a healthcare professional

If you’re interested in using this drug, search here to find a doctor who might prescribe it.

Humalog: Generic or biosimilar

Humalog and Humalog Mix are brand-name medications. Humalog contains the active drug insulin lispro. Humalog Mix contains the active drugs insulin lispro and insulin lispro protamine. Both Humalog and Humalog Mix are biologic drugs

Biologics are made from parts of living cells. This is different from traditional drugs, which are made from chemicals. The active drug in traditional brand-name medications can be copied exactly and made available as a generic. However, biologics can’t be copied exactly. For this reason, biologics have biosimilars instead of generics.

A biosimilar medication is a drug that’s similar to a brand-name biologic drug (the parent drug). Biosimilars are considered as safe and effective as the brand-name biologic drug. As with generics, biosimilars often cost less than brand-name drugs.

The FDA approved many insulins, including Humalog, before biologics became available for approval. This also means that certain insulin products became available before biosimilar products did.

However, the manufacturer of Humalog was able to authorize generic versions of its insulin products. The generic insulins are identical to the branded insulin products, except they have generic names.

The manufacturer of Humalog and Humalog Mix has made the following generic forms available:

  • insulin lispro injection, multiple-use vial
  • insulin lispro injection, single-use KwikPen
  • insulin lispro injection, single-use Junior KwikPen
  • insulin lispro protamine and insulin lispro injectable suspension mix 75/25, single-use KwikPen

If you’d like to know more about these generic forms, ask your doctor or pharmacist.

Humalog: Alternatives

Doctors may prescribe drugs other than Humalog for your condition. (Throughout this article, the term “Humalog” is often used to describe both Humalog and Humalog Mix.) Certain drugs may work better for you than others.

Humalog is used to help manage blood sugar levels in people who have diabetes. Here’s a summary of other drugs that doctors sometimes prescribe for this condition.

Humalog vs. NovoLog and other drugs

To learn more about some alternatives of Humalog, view the following articles:

Your doctor can tell you about other similar drugs, such as insulin glargine (Lantus), insulin aspart (Fiasp), insulin glulisine (Apidra), and regular insulin (Novolin R, Humulin R).

For additional information about alternatives to Humalog, ask your doctor. They can tell you about other medications that could be prescribed for your condition.

Humalog: Sliding scale

Doctors may determine your Humalog dosage using a sliding scale.

A sliding scale uses a chart to display a range of low, moderate, or high insulin dosages. The actual dosage you’ll use from this chart can vary based on a few factors. These include:

  • your blood sugar level before a meal
  • the amount of carbohydrates you’ll consume

The sliding scale method is commonly used to manage blood sugar levels in people staying in the hospital. However, doctors aren’t likely to prescribe Humalog on a sliding scale for people using the drug at home.

If you have questions about sliding scales with Humalog or Humalog Mix, talk with your doctor.

Humalog: Side effects

As with most drugs, it’s possible to have side effects with Humalog. (Throughout this article, the term “Humalog” is often used to describe both Humalog and Humalog Mix.) These can include some mild side effects but also some serious ones.

To learn more about Humalog’s side effects, talk with your doctor or pharmacist. They may also provide information about managing certain side effects of this drug.

Note: The Food and Drug Administration (FDA) tracks side effects of drugs it has approved. If you would like to notify the FDA about a side effect you’ve had with Humalog, you can do so through MedWatch.

Mild and serious side effects

Mild and serious side effects of Humalog are listed below. This article does not include all of Humalog’s possible side effects.

Mild side effects

Mild side effects* of Humalog may include:

Most times, mild side effects of a drug go away within a few days or a couple of weeks. Talk with your doctor or pharmacist if any side effects become severe or don’t go away.

* This is not a complete list of Humalog’s mild side effects. To learn about other mild side effects of this drug, ask your doctor or pharmacist. Or you can view the prescribing information for Humalog U-100 and U-200, Humalog Mix 75/25, and Humalog Mix 50/50.
† To learn more about allergic reaction, see below.

Serious side effects

Serious side effects of Humalog may include:

Serious side effects from Humalog aren’t common, but they are possible. If you have serious side effects, call your doctor right away. However, if you’re having a medical emergency or your symptoms feel life threatening, call 911 or a local emergency number.

* To learn more about allergic reaction, see below

Allergic reaction

As with most drugs, some people can have an allergic reaction after taking Humalog. A more severe allergic reaction is rare but possible.

Allergic reaction was a less common side effect in clinical studies of Humalog U-100 and U-200, Humalog Mix 75/25, and Humalog Mix 50/50.

Possible symptoms of mild and serious allergic reactions are listed in the table below.

Mild allergic reaction symptoms Serious allergic reaction symptoms
flushing swelling under your skin, possibly in your hands, feet, lips, or eyelids
rash swelling in your throat or mouth
itching trouble breathing

If you have an allergic reaction to Humalog, call your doctor right away. This is important because the reaction could become severe.

However, if you’re having a medical emergency or your symptoms feel life threatening, call 911 or a local emergency number.

Humalog: Questions you may have

Here are some common questions about Humalog and brief answers to them. If you’d like to know more about these topics, ask your doctor.

Throughout this article, the term “Humalog” is often used to describe both Humalog and Humalog Mix.

What is the peak time for Humalog?

The peak time for Humalog is about 1 to 3 hours. (Peak time is the amount of time it takes a drug to reach its maximum effect after being administered.)

If you have more questions about the peak time of Humalog or Humalog Mix, talk with your doctor or pharmacist.

Is Humalog a fast-acting insulin?

Yes, Humalog is a fast-acting insulin, which is also called a “rapid-acting” insulin.

Humalog is a type of fast-acting insulin called mealtime insulin. The drug is considered fast acting because it starts working within 15 minutes of being administered. Humalog is meant to be injected within 15 minutes before or right after a meal.

If you have questions about Humalog as a fast-acting insulin, talk with your doctor or pharmacist. To learn how Humalog works, see the “Humalog: How it works” section below.

Does Humalog cure diabetes?

No, Humalog does not cure diabetes. At this time, type 1 diabetes and type 2 diabetes don’t have a cure.

However, clinical studies have shown Humalog is effective for managing blood sugar levels. To learn more, see the prescribing information for Humalog U-100 and U-200, Humalog Mix 75/25, and Humalog Mix 50/50.

Your doctor or pharmacist can also advise you on what to expect with Humalog treatment.

Humalog: Dosage

Below, you’ll find dosages that are commonly recommended for Humalog. However, you should take the dosage your doctor prescribes for you. They’ll recommend the dosage that’s best for your needs.

The dosage of Humalog that your doctor prescribes will depend on factors such as:

  • the strength of Humalog you’ll use
  • your weight
  • other medications you take, including other types of insulin
  • any health conditions you have
  • whether you have type 1 diabetes or type 2 diabetes
  • when and how much you exercise
  • the amount of carbohydrates you consume

Humalog’s forms and strengths

Two types of Humalog are available: Humalog and Humalog Mix. Each type comes in different forms and strengths.

Humalog

Humalog’s forms and strengths are described in the following table.

Forms Strengths* Ways to be injected
solution in 3-milliliter (mL) or 10-mL multiple-use vial • U-100 subcutaneous injection, given by insulin syringes or an insulin pump
IV infusion, given by a healthcare professional, usually in a hospital†
solution in 3-mL single-use cartridge • U-100 • subcutaneous injection, given by a multiple-use insulin pen
solution in 3-mL single-use injection pen, called a KwikPen • U-100
• U-200
• subcutaneous injection, given by single-use needles that attach to the injection pen
solution in 3-mL single-use injection pens, called Junior KwikPen and Tempo Pen • U-100 • subcutaneous injection, given by single-use needles that attach to the injection pen

* U-100 is 100 units per mL. U-200 is 200 units per mL.
† If you need Humalog while in a hospital, you may receive the drug as an IV infusion. Your doctor will determine if you need this type of Humalog. In this case, they’ll decide the dose that’s right for an infusion.

Humalog Mix

Humalog Mix comes as a 75/25 mixture, which contains 75% insulin lispro protamine and 25% insulin lispro. It also comes as a 50/50 mixture, which contains 50% insulin lispro protamine and 50% insulin lispro.

Humalog Mix’s forms and strengths are described in the following table.

Forms Strengths* Ways to inject
liquid suspension in 10-mL multiple-use vial U-100 subcutaneous injection, given by insulin syringes
liquid suspension in 3-mL single-use injection pen, called a KwikPen U-100 subcutaneous injection, given by single-use needles that attach to the injection pen

* U-100 is 100 units per mL.

Humalog’s recommended dosages

Recommended dosages for Humalog in adults and children are described below.

Adult dosage

Humalog and Humalog Mix are approved to help manage blood sugar levels in adults with type 1 or type 2 diabetes.

Dosage for type 1 diabetes

The manufacturer of Humalog and Humalog Mix has not provided a dosage for type 1 diabetes.

However, the American Diabetes Association (ADA) recommends the dosages below for this use. This is based on a person’s weight in kilograms (kg). One kg is about 2.2 pounds (lb).

Drug Total daily insulin dosage Dose Frequency
Humalog 0.4 units to 1 unit of insulin per kg of body weight 50% of the total daily insulin dosage, divided over each meal within 15 minutes before or right after a meal, for as many meals as your doctor advises each day
Humalog Mix 0.4 units to 1 unit of insulin per kg of body weight 50% of the total daily insulin dosage, divided over each meal within 15 minutes before or right after two meals each day

Here’s an example dosage calculation for a person weighing 175 lb (about 80 kg). A doctor prescribes a total daily insulin dosage of Humalog of 0.5 units per kg. This means the total daily insulin dosage would be 40 units.  

The doctor advises this person to take half of their total daily insulin dosage as a rapid-acting insulin. This means the dose of Humalog would be 20 units. The doctor further advises to divide the dose over two meals. So, the person would take a 10-unit dose of Humalog at each of the two daily meals.

Your doctor will advise you on the dosage that’s right for you. They may adjust your dosage of Humalog or Humalog Mix based on your blood sugar levels.

Dosage for type 2 diabetes

The manufacturer of Humalog and Humalog Mix has not provided a dosage for type 2 diabetes.

However, the American Diabetes Association (ADA) recommends the dosages below for this use.

Drug Dose Frequency
Humalog two options:
• 4 units daily
• an amount equal to 10% of your daily long-acting insulin dosage
within 15 minutes before or right after the largest meal each day
Humalog Mix two options:
• 4 units daily
• an amount equal to 10% of your daily long-acting insulin dosage
within 15 minutes before or right after the largest meal each day, or after two meals each day if your doctor advises it

Your doctor will advise you on the dosage that’s right for you. They may adjust your dosage of Humalog or Humalog Mix based on your blood sugar levels.

Child dosage

Humalog is approved to help manage blood sugar levels in children ages 3 years and older with type 1 diabetes. Humalog Mix is not approved for use in children.

The manufacturer of Humalog has not provided a dosage for type 1 diabetes.

However, the American Diabetes Association (ADA) recommends the dosage below for this use. This is based on a child’s weight in kilograms (kg). One kg is about 2.2 pounds (lb).

Total daily insulin dosage Dose Frequency
0.4 units to 1 unit of insulin per kg of body weight 50% of the total daily insulin dosage, divided over each meal within 15 minutes before or right after a meal, for as many meals as your child’s doctor advises each day

Here’s an example dosage calculation for a child weighing 88 lb (about 40 kg). A doctor prescribes a total daily insulin dosage of Humalog of 0.5 units per kg. This means the total daily insulin dosage would be 20 units.

The doctor advises to give the child half of their total daily insulin dosage as a rapid-acting insulin. This means the child’s dose of Humalog would be 10 units. The doctor also advises to divide the dose over two meals. So, the child would be given a 5-unit dose of Humalog at each of the two daily meals.

Your child’s doctor will advise you on the dosage that’s right for your child. They may adjust your child’s dosage of Humalog or Humalog Mix based on their blood sugar levels.

Dosage considerations

Below are some things to consider about Humalog’s dosage.

Missing a dose. Humalog is used to help manage blood sugar spikes (sharp increases) that happen when you eat. You’ll typically use Humalog within 15 minutes before the start of a meal. It’s also possible to use it right after a meal.

If you forget a dose, you can check your blood sugar levels after the meal to decide whether you need a Humalog dose. Then, you can either take your missed dose or wait until you would typically inject the next dose.

If you aren’t sure whether to take a dose of Humalog or skip it, talk with your doctor. They can tell you what your blood sugar level should be after eating.

Try these medication reminder options to help avoid missing doses. You could also set an alarm, use a timer, or download a reminder app on your phone.

Length of treatment. Doctors typically prescribe Humalog as a long-term treatment. You’ll likely use it long term if you and your doctor feel it’s safe and effective for your condition.  

Humalog: How to take

Your doctor will recommend how you should use Humalog. It’s important to use the drug exactly as your doctor instructs.

Humalog comes in two forms:

  • Humalog, which is a solution that’s given by subcutaneous injection or IV infusion
  • Humalog Mix, which is a liquid suspension that’s given by subcutaneous injection

Humalog injections

A healthcare professional will show you or a caregiver how to give Humalog injections at home.

Humalog injections are given under the skin of your upper arms, abdomen, buttocks, or thigh.

For more information about how to inject Humalog, visit the manufacturer’s website. You can also refer to the “Instructions for use” in the prescribing information for Humalog U-100 and U-200, Humalog Mix 75/25, and Humalog Mix 50/50.

Humalog infusions

Humalog infusions are given by a healthcare professional as a slow injection into your vein. These are typically given in a hospital. You won’t give yourself infusions of Humalog.

Questions about taking Humalog

Here’s a list of common questions related to taking Humalog.

  • How much Humalog should I take? The amount of Humalog you’ll use depends on several factors. Among others, these factors include whether you have type 1 diabetes or type 2 diabetes and the strength of Humalog you’re prescribed. To learn more, see the “Humalog: Dosage” section above.
  • When should I take Humalog? You’ll typically inject Humalog within 15 minutes before a meal. It’s also possible to inject it right after a meal. Try these medication reminder options to help avoid missing doses of Humalog. You could also set an alarm, use a timer, or download a reminder app on your phone.
  • Do I need to take Humalog with food? Yes, you should always use Humalog with food. Your doctor will prescribe whether you should inject the drug within 15 minutes before a meal or right after one.
  • Is there a best time of day to administer Humalog? Yes, your doctor will prescribe the time for you to administer Humalog. You’ll typically take Humalog within 15 minutes before a meal. You may also inject the drug right after a meal.

Humalog: Price

As with other medications, the prices for Humalog may vary. The drug’s price will depend on factors such as:

Cost considerations for Humalog

Here are some things to consider when looking into the cost of Humalog.

Option for a 90-day supply. For some drugs, it’s possible to get a 90-day supply. If this option is approved by your insurance company, it can help lower the cost of the drug. It can also help you avoid frequent trips to your pharmacy. If you’d like to learn more about this option, ask your doctor, pharmacist, or insurance company.

Need for prior authorization. Before insurance coverage for Humalog is approved, your insurance company may require prior authorization. In this case, your doctor and insurance company will communicate about your prescription for Humalog. Then, the insurance company will decide whether the drug will be covered. To find out whether you need prior authorization for Humalog, contact your insurance company.

Possible cost assistance options. Financial assistance to help lower the cost of Humalog is available. Lilly’s Insulin Value Program for Humalog may help reduce its cost. To learn more and see whether you’re eligible for support, call 833-808-1234 or visit the manufacturer’s website. Also, check out this article to learn about ways to save on prescription drugs.

Use of a mail-order pharmacy. Humalog may be dispensed through mail-order pharmacies. Getting your prescription through a mail-order pharmacy could lower its cost. It can also allow you to get the drug without leaving home. To find out more about this option, check with your doctor, pharmacist, or insurance company.

Availability of a generic or biosimilar form. Humalog and Humalog Mix are biologic drugs. The active drug in traditional brand-name medications can be copied exactly and made available as a generic. Biologics can’t be copied exactly. For this reason, biologics have biosimilars instead of generics.

With Humalog, the manufacturer authorized generic versions of its insulin product to be made. The generic insulins are identical to the branded insulin product, except they have generic names. Generics often cost less than brand name drugs.

See the “Humalog: Generic or biosimilar” section above for more information. Also, check your insurance plan because it might cover just one form or the other.

Humalog: How it works

Humalog and Humalog Mix are approved to help manage blood sugar levels in the following conditions:

Use in Condition treated Medication
adults type 1 diabetes
type 2 diabetes
Humalog or Humalog Mix
children ages 3 years and older • type 1 diabetes Humalog

Humalog Mix has a limitation of use. For details about this and diabetes, see the “Humalog: Uses” section below.

In some people with diabetes, the body doesn’t make enough insulin (a hormone). In others, the insulin it does make no longer helps the body break down glucose (blood sugar) as it should.

In either case, the level of sugar in the blood can rise. Over time, high levels of blood sugar may cause serious health problems. Examples include damage to the eyes, heart, kidneys, and nerves.

Humalog is a type of rapid-acting insulin called mealtime insulin. Rapid-acting insulin is sometimes called fast-acting insulin. Humalog is used to help manage blood sugar spikes (sharp increases) that happen when you eat.

Humalog is a human-made version of the insulin made naturally in your body. Like natural insulin, Humalog helps to move blood sugar into the body’s cells. Once it’s in the cells, blood sugar is used as an energy source. This helps lower your blood sugar level.

How long does Humalog take to start working?

Humalog starts working within 15 minutes of an injection. Your doctor will likely have you check your blood sugar level 1 to 2 hours after a meal to see if Humalog is working. They can tell you what your blood sugar level should be after eating.

How long does Humalog last in your system?

Humalog lasts in your system for about 4 to 6 hours. Humalog Mix lasts in your system for about 22 hours.

Humalog and Humalog Mix contain slightly different ingredients. While both forms contain insulin lispro, Humalog Mix also contains insulin lispro protamine. This additional ingredient is a longer-acting form of insulin lispro. It allows the drug to last longer in the body.

Humalog: Uses

Prescription drugs, such as Humalog, are approved by the Food and Drug Administration (FDA) to treat certain conditions. Doctors sometimes prescribe drugs off-label for other conditions. With off-label use, doctors prescribe a drug for a purpose other than what it’s approved for.

Using Humalog for diabetes

Humalog and Humalog Mix are approved to help manage blood sugar levels in the following conditions:

Use in Condition treated Medication
adults type 1 diabetes
type 2 diabetes
Humalog or Humalog Mix
children ages 3 years and older • type 1 diabetes Humalog

Humalog Mix has a limitation of use. For details about this, see the “Limitation of use for Humalog Mix” section below.

About type 1 diabetes

With type 1 diabetes, the pancreas doesn’t make enough of a hormone called insulin. This hormone typically helps your body break down glucose (blood sugar). Insulin does this by moving blood sugar into the body’s cells. Once it’s in the cells, blood sugar is used as an energy source.

Because the pancreas doesn’t make enough insulin, the level of sugar in your blood can rise. Over time, high levels of blood sugar may cause serious health problems. Examples include damage to the eyes, heart, kidneys, and nerves.

Symptoms of type 1 diabetes include:

  • increased hunger and thirst
  • urinating more often than usual
  • fatigue
  • blurred vision
  • unintentional weight loss

About type 2 diabetes

With type 2 diabetes, the pancreas makes insulin. However, it doesn’t help your body break down glucose (blood sugar) as it should.

As with type 1 diabetes, the level of sugar in your blood can rise. Over time, high levels of blood sugar may cause serious health problems. Examples include damage to the eyes, heart, kidneys, and nerves.

Symptoms of type 2 diabetes are generally the same as symptoms of type 1 diabetes. For details, see “About type 1 diabetes” above.

Limitation of use for Humalog Mix

The manufacturer of Humalog Mix has noted a limitation to the drug’s use. This is a situation in which treatment with the drug may not be recommended.

Both Humalog and Humalog Mix contain the active drug insulin lispro. However, Humalog Mix also contains the active drug insulin lispro protamine. This drug is a longer-acting form of insulin lispro. Insulin lispro protamine allows the drug to last longer in the body.

The percentages of these active drugs in Humalog Mix cannot be changed.* For this reason, doctors aren’t able to change the dosage of just one of the two active drugs or the other.

Your doctor will monitor how well your blood sugar is managed with Humalog Mix. They may need to adjust your dosage of longer-acting insulin but not change the dosage of insulin lispro. In this case, they may switch you to an insulin other than Humalog Mix for your diabetes.

* Humalog Mix 75/25 contains 75% insulin lispro protamine and 25% insulin lispro. Humalog Mix 50/50 contains 50% insulin lispro protamine and 50% insulin lispro.

Using Humalog with other drugs

Doctors may prescribe Humalog in combination with other diabetes medications to help manage your blood sugar levels.

If you have type 1 diabetes, you’ll likely use Humalog with other types of insulin. These insulins will help manage your blood sugar levels between meals and at night. Examples of other insulins that may be used with Humalog include:

  • intermediate-acting insulin, such as regular insulin (Humulin N, Novolin N)
  • long-acting insulin, such as insulin glargine (Lantus)

If you have type 2 diabetes, you’ll likely use Humalog with non-insulin medications. A few examples of non-insulin medications for diabetes include:

  • biguanides, such as metformin (Fortamet, Glumetza, Riomet)
  • sulfonylureas, such as glimepiride (Amaryl)
  • dipeptidyl peptidase-4 (DPP-4) inhibitors, such as sitagliptin (Januvia)

To learn more about the drug combination that’s right for treating your diabetes, talk with your doctor.

Using Humalog in children

Humalog is approved to treat type 1 diabetes in children ages 3 years and older. For details about this condition, see “About type 1 diabetes” above.

Humalog is not approved to treat type 2 diabetes in children. Humalog Mix is not approved for any use in children.

Finding a healthcare professional for Humalog

If you’re interested in using Humalog, you can find a doctor who might prescribe it by searching here. You can prepare for your appointment by visiting Healthgrades’ appointment guide for type 1 diabetes or type 2 diabetes.

Humalog: Consuming alcohol during treatment

Alcohol may interact with Humalog.

This interaction can occur because alcohol impacts blood sugar levels. So, drinking alcohol while using Humalog can make it difficult to manage your blood sugar. It can also make it difficult to know whether Humalog is working to treat your diabetes.

For these reasons, it’s best to talk with your doctor about drinking alcohol during Humalog treatment. They can tell you whether there’s a safe amount to consume while using the drug.

Humalog: Interactions

Humalog may interact with other medications. (Throughout this article, the term “Humalog” is often used to describe both Humalog and Humalog Mix.) However, the drug isn’t known to interact with any supplements or foods.

Different interactions can cause different effects. Some interactions can interfere with a drug’s effectiveness. Others can increase a drug’s side effects or cause them to be severe.

Before you start Humalog, be sure to tell your doctor about any medications, herbs, vitamins, or supplements you take. They can check for any possible interactions between these products and Humalog.

If any of the interactions listed below might pertain to you, talk with your doctor. They can tell you what you need to do to avoid the interaction.

  • Humalog and certain other medications. Because Humalog may interact with the following drugs, your doctor may recommend you do not take it with these drugs. Examples include:
    • other diabetes drugs, such as rosiglitazone (Avandia) and pioglitazone (Actos)
    • hormonal birth control, such as birth control pills
    • corticosteroids, such as prednisone (Rayos) and methylprednisolone (Medrol)
    • angiotensin-converting enzyme (ACE) inhibitors, such as enalapril (Vasotec) and benazepril (Lotensin)
    • angiotensin II receptor blockers (ARBs), such as valsartan (Diovan) and losartan (Cozaar)
    • beta-blockers, such as propranolol (Inderal) and metoprolol (Lopressor, Toprol XL)
    • cholesterol-lowering drugs, such as fenofibrate (Tricor) and niacin
    • atypical antipsychotics, such as clozapine (Clozaril) and risperidone (Risperdal)
    • monoamine oxidase inhibitors (MAOIs), such as selegeline (Emsam) and isocarboxazid (Marplan)
    • salicylates, such as aspirin
    • diuretics, such as hydrochlorothiazide (Microzide) and chlorthalidone (Thalitone)
    • somatostatin analogs, such as octreotide (Mycapssa, Sandostatin)
    • thyroid hormones, such as levothyroxine (Synthroid)
    • certain antibiotics, such as sulfamethoxazole/trimethoprim (Bactrim) and isoniazid
    • the antidepressant drug fluoxetine (Prozac)
    • the abnormal heart rhythm drug disopyramide (Norpace)
    • the mood stabilizer drug lithium (Lithobid)
  • Humalog and herbs and supplements. Humalog isn’t known to interact with any herbs or supplements. If you have questions about taking certain herbs or supplements with Humalog, talk with your doctor or pharmacist.
  • Humalog and foods. Humalog isn’t known to interact with any foods. If you have questions about eating specific foods with Humalog, talk with your doctor or pharmacist.

For information about drug-condition interactions, see the “Humalog: Precautions” section below.

Humalog: Using while pregnant

It’s not known for sure whether Humalog or Humalog Mix is safe to use while pregnant. Neither drug has been tested in enough clinical studies to know for certain. For information from clinical studies, see the prescribing information for Humalog U-100 and U-200, Humalog Mix 75/25, and Humalog Mix 50/50.

However, the American Diabetes Association (ADA) recommends using insulin to manage blood sugar levels while pregnant. The ADA generally considers insulins, including Humalog and Humalog Mix, to be safe and effective for use during pregnancy.

If you’re pregnant or planning to become pregnant, talk with your doctor. They can discuss the risks and benefits of Humalog use during pregnancy.

Humalog and birth control needs

Doctors aren’t sure whether it’s safe to use Humalog during pregnancy. Talk with your doctor about your birth control needs with Humalog if you’re sexually active and you or your partner can become pregnant. Your doctor can recommend if you should use birth control with this medication.

Hormonal birth control pills can make Humalog less effective in lowering your blood sugar levels. If you use birth control during Humalog treatment, your doctor may adjust your Humalog dosage. They may also have you check your blood sugar levels more frequently to make sure Humalog is working.

If you have questions about birth control and Humalog, talk with your doctor.

Humalog: Using while breastfeeding

Humalog or Humalog Mix may pass into breast milk. However, it’s not known whether this causes side effects in a breastfed child.

In general, the American Diabetes Association (ADA) considers insulins, including Humalog and Humalog Mix, to be safe for use while breastfeeding.

If you’re breastfeeding or planning to breastfeed while using Humalog, talk with your doctor. They can advise you on the risks and benefits of using the drug during this time.

Humalog: Precautions

Tell your doctor about your health history before starting treatment with Humalog. (Throughout this article, the term “Humalog” is often used to describe both Humalog and Humalog Mix.) Your doctor may not recommend this medication if you have certain factors affecting your health or specific medical conditions. These situations are considered drug-condition interactions.

These factors and conditions include those listed below.

Low blood potassium level. Before using Humalog, tell your doctor if you have a low blood potassium level. Humalog may cause a low blood potassium level as a side effect, which could lower your level further.

Your doctor may check your blood potassium levels more often than usual while you use Humalog.

Low blood sugar level. Doctors will advise against using Humalog during an episode of low blood sugar. This is because Humalog will lower your blood sugar level even further. In some cases, having severely low blood sugar can be life threatening.

Your doctor will tell you how to manage an episode of low blood sugar. They’ll also tell you when it’s safe to resume using Humalog.

Liver or kidney problems. Before using Humalog, tell your doctor if you have liver or kidney problems. Examples include liver failure and kidney failure. Liver or kidney problems can increase your risk of low blood sugar with Humalog.

Your doctor may adjust your dosage of Humalog to lessen the risk of low blood sugar.

Heart failure and use of thiazolidinediones (TZDs). Before using Humalog, tell your doctor if you have heart failure and take a type of diabetes drug called a TZD. Examples of TZDs include pioglitazone (Actos) and rosiglitazone (Avandia). When used with TZDs, Humalog can increase your risk of swelling, which could worsen heart failure.

Your doctor can advise whether it’s safe for you to use Humalog if you have heart failure and take TZDs.

Allergic reaction. Your doctor will likely not prescribe Humalog if you’ve had an allergic reaction to it or any of its ingredients. To find out about other treatment options, talk with your doctor.

Pregnancy. If you’d like additional information about using Humalog while pregnant, view the “Humalog: Using while pregnant” section above.

Breastfeeding. If you’d like additional information about using Humalog while breastfeeding, view the “Humalog: Using while breastfeeding” section above.

To learn more about effects of Humalog that could be harmful, see the “Humalog: Side effects” section above.

Humalog: Overdose

Serious effects can occur if you use more than the recommended dosage of Humalog or Humalog Mix. Do not use more Humalog than your doctor recommends.  

Symptoms of overdose

Symptoms that an overdose could cause include:

What to do in case of overdose

Call your doctor if you think you’ve taken too much of this drug. Also, you can call the American Association of Poison Control Centers at 800-222-1222 or use its online tool. However, if your symptoms are severe, call 911 or a local emergency number. Or go to the nearest emergency room right away.

Humalog: Expiration, storage, and disposal

Here’s some information about Humalog’s expiration date, as well as how to store and dispose of the drug.

Expiration. Your pharmacist will add an expiration date to the label on Humalog’s packaging. This date is usually 1 year from the date the medication was dispensed to you. Expiration dates help ensure that a medication is effective during a period of time.

The Food and Drug Administration (FDA) advises that you avoid taking expired drugs. If you have an unused medication and it’s past the drug’s expiration date, talk with your pharmacist. They can let you know whether you might still be able to use the medication.

Storage. Many factors determine how long a medication remains good to use. These factors include how and where you store the drug.

Never store Humalog and Humalog Mix in the freezer. See the tables below for information on storing Humalog and Humalog Mix. Storage factors include whether the product is unopened or opened, the form, and the temperature for storing.

Unopened product Form Refrigerator or room temperature Expiration
• Humalog • vials
• injection pens
• cartridges
• refrigerator: 36°F to 46°F (2°C to 8°C) will last until expiration date printed on packaging
• Humalog Mix • vials
• injection pens
• refrigerator: 36°F to 46°F (2°C to 8°C) will last until expiration date printed on packaging
• Humalog • vials
• injection pens
• cartridges
• room: up to 86°F (30°C) good to use for 28 days
• Humalog Mix • vials • room: up to 86°F (30°C) good to use for 28 days
• Humalog Mix • injection pens • room: up to 86°F (30°C) good to use for 10 days
Opened product Form Refrigerator or room temperature Expiration
• Humalog • vials • refrigerator: 36°F to 46°F (2°C to 8°C)
• room: up to 86°F (30°C)
good to use for 28 days
• Humalog • injection pens*
• cartridges*
• room: up to 86°F (30°C) good to use for 28 days
• Humalog Mix • vials • refrigerator: 36°F to 46°F (2°C to 8°C)
• room: up to 86°F (30°C)
good to use for 28 days
• Humalog Mix • injection pens* • room: up to 86°F (30°C)

good to use for 10 days

* Pens and cartridges should not be refrigerated again once the product has been opened or used.

Disposal. Dispose of any used syringes, needles, or injection pens right after using them. You can safely dispose of these items in an FDA-approved sharps container. Doing so helps prevent others, including children and pets, from accidentally taking the drug. It also helps them avoid harm from needles.

If you’d like to buy a sharps container, you can find options online. Or ask your doctor, pharmacist, or health insurance company where you can purchase one. Your pharmacist can give you more information about disposing of Humalog. Also, check out this page for several tips on safe medication disposal.

Humalog: Questions for your doctor

If you have questions about Humalog, talk with your doctor. They can help advise you on whether Humalog could be a suitable treatment option for you.

Here’s a list of questions you may want to ask your doctor:

  • Can I switch from Humalog to Humalog Mix or vice versa?
  • Will I take other diabetes medications with Humalog?
  • How can I manage injection site reactions with Humalog?

Your doctor may also tell you about other treatment options for your condition. You may find the following articles helpful in learning about alternative drugs for:

You can also view our selection of videos on diabetes.

Disclaimer: Healthgrades 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.

Medical Reviewer: Victor Nguyen, PharmD, MBA
Last Review Date: 2022 Aug 18
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.