Humulin N (isophane insulin human) is a prescription brand-name medication. It’s approved by the Food and Drug Administration (FDA) to help manage blood sugar levels in adults and children who have type 1 or type 2 diabetes.

With diabetes, your body either stops making or stops responding to a hormone called insulin. Your body needs insulin to move sugar from your blood into your cells, which use sugar for energy. Diabetes can cause increased blood sugar levels.

If you and your doctor believe Humulin N is working to help manage your blood sugar levels, you’ll likely use the drug long term.

Here are the basics on Humulin N:

  • Active ingredient: isophane insulin human, which is a biologic
  • Drug class: intermediate-acting insulin
  • Drug forms: liquid suspension given as a subcutaneous injection by using either:
    • single-use KwikPens
    • multiple-dose vials with insulin syringes
  • Available as biosimilar: no

Read on for more information on Humulin N and its use in treating diabetes.

You should use Humulin N according to your doctor’s instructions. Below are details on some common dosages for Humulin N, as well as ways the drug is commonly used.

Dosage for KwikPens and vials

The patient package insert for Humulin N doesn’t have specific dosage recommendations for treating either type 1 or type 2 diabetes. Your doctor will personalize your dose based on your blood sugar levels, insulin needs, and blood sugar goals. Your dose may also vary depending on whether you’re using other insulins or diabetes medications in addition to Humulin N as part of your diabetes treatment plan.

Your dose of Humulin N may need to be adjusted due to factors such as:

  • changes in activity level
  • changes in diet
  • gaining or losing weight
  • increased stress
  • becoming sick

Your doctor will closely monitor your blood sugar levels and adjust your Humulin N dose as needed.

How to use

Here’s some information on using Humulin N KwikPens and vials.

Using a KwikPen. With Humulin N KwikPens, you use a dial on the pen to select the dose your doctor prescribes for you. You’ll also need to get pen needles when you pick up your prescription. Pen needles are attached to the KwikPen so you can inject your dose. Your doctor or pharmacist should show you how to use the KwikPen the first time you get Humulin N.

For an illustrated guide on using KwikPens, see the manufacturer’s site.

Using a vial. With Humulin N vials, you use a syringe to draw up your dose. In addition, you’ll need needles to attach to the syringe. Your doctor or pharmacist should show you how to use Humulin N vials and syringes the first time you get Humulin N.

For an illustrated guide on using the vials, see the manufacturer’s site.

Where to inject

Humulin N is meant to be given only as a subcutaneous injection. You shouldn’t inject the medication into a muscle or directly into a vein. If you do, your body may not absorb Humulin N. These incorrect injections may also cause side effects such as changes in blood sugar levels.

Be sure to use one of the following body sites when you inject Humulin N:

  • belly
  • thighs
  • upper arms
  • buttocks

It’s recommended that you rotate your injection sites. This means using a different site for each dose. Doing so may help you avoid injection site reactions. (For more information, see “Humulin N side effects” below.)

How often to use

How often you use Humulin N will depend on the dosing instructions your doctor gives you. They’ll vary from person to person.

If you and your doctor believe Humulin N is working to help manage your blood sugar levels, you’ll likely use the drug long term.

The use of Humulin N for diabetes (its only approved use) may cause side effects that are mild or serious. The lists below include some of the main side effects that have been reported with Humulin N. For information on other potential side effects of the drug, talk with your doctor or pharmacist. You can also refer to Humulin N’s patient package insert.

Note: After the Food and Drug Administration (FDA) approves a medication, it tracks side effects of the drug. If you develop a side effect while taking Humulin N and would like to inform the FDA, visit MedWatch.

Mild side effects

Mild side effects can occur from taking Humulin N. Hypoglycemia (low blood sugar) and injection site reactions are two of the most common. With injection site reactions, you may have redness, swelling, change in skin color, heat, or pain near the injection site. There are other mild side effects, but these are less common with Humulin N.

Mild side effects seen in people taking Humulin N include:

  • hypoglycemia
  • injection site reactions
  • lipodystrophy (skin dimpling near the injection site)
  • itchiness
  • rash
  • weight gain
  • swelling, particularly in your hands or feet

These side effects of Humulin N may be temporary, lasting a few days or weeks. But if they last for a longer time, or if they bother you or become severe, it’s important to talk with your doctor or pharmacist.

Serious side effects

Serious side effects from taking Humulin N aren’t common, but they can occur.

Serious side effects reported in people taking Humulin N include:

Call your doctor right away if you develop serious side effects while using Humulin N. If the side effects seem life threatening or you think you’re having a medical emergency, call 911 or your local emergency number immediately.

Below are answers to some frequently asked questions about using Humulin N for diabetes.

What type of insulin is Humulin N?

Humulin N is a type of regular insulin.

Humulin N contains isophane insulin human. Humulin N is made as an isophane liquid suspension, which means it’s released slowly into your body over time. Humulin N helps manage blood sugar for about 12 to 18 hours, so it’s an intermediate-acting insulin.

As a comparison, another insulin human product called Humulin R releases more quickly and requires more frequent injections. It helps manage blood sugar for about 3 to 6 hours, so it’s a short-acting insulin.

If you have additional questions about types of insulin, including Humulin N, talk with your doctor or pharmacist.

Can Humulin N be used for gestational diabetes?

Yes. According to a recommendation from the American Diabetes Association, insulin is the standard of care for managing blood sugar levels during pregnancy. The recommendation also applies to gestational diabetes, a type of short-term diabetes that can occur while pregnant. Humulin N, including the Humulin N KwikPen, is mentioned as a potential insulin option for treating gestational diabetes.

If you’d like to learn more about using Humulin N for gestational diabetes, talk with your doctor. They can advise you on the right treatment plan for you.

With diabetes, your body either stops making or stops responding to a hormone called insulin. Your body needs insulin to move sugar from your blood into your cells, which use sugar for energy. Diabetes can cause increased blood sugar levels. Over time, high blood sugar can damage your nerves and organs such as the heart, eyes, and kidneys.

Symptoms of diabetes

When you have diabetes, you have a high blood sugar level, which can cause other symptoms of diabetes.

Besides high blood sugar, diabetes symptoms may vary from person to person. The most common symptoms of diabetes include:

  • severe fatigue (lack of energy)
  • being hungrier than usual
  • being thirstier than usual
  • blurred vision
  • urinating more often than usual, especially at night

With type 1 diabetes, your body can’t make insulin. Symptoms usually appear abruptly and begin dramatically. Type 1 diabetes may develop at any age, but it’s most common in children and adolescents.

With type 2 diabetes, your body can make insulin but isn’t able to use it effectively. Type 2 diabetes is the most common type of diabetes. It’s most often seen in adults but can occur at any age. Symptoms with type 2 diabetes typically develop slowly. Early on in type 2 diabetes, you may not notice any symptoms.

Who Humulin N is prescribed for

Humulin N is approved by the Food and Drug Administration (FDA) to help manage blood sugar levels in adults and children who have type 1 or type 2 diabetes.

Humulin N is prescribed to treat diabetes in adults and children. Specifically, it’s used to help manage blood sugar levels in people who have type 1 or type 2 diabetes.

What happens with diabetes

After you eat, your stomach breaks down food. Glucose (sugar) is released when food is digested. When this happens, your body releases insulin in response.

Insulin is a type of hormone that helps move glucose out of your blood and into your body’s cells. Glucose is turned into energy inside your cells.

An organ called the pancreas makes insulin naturally. If you have type 1 diabetes, your pancreas isn’t able to make insulin. If you have type 2 diabetes, your pancreas may still make insulin, but your cells no longer respond to insulin like normal. This is called insulin resistance. Over time, it’s possible that type 2 diabetes could cause your pancreas to stop making insulin altogether.

If your body stops making insulin, or your cells stop responding to it, your blood sugar levels can increase. Left untreated, they can become too high, which can damage your organs. And your body may not get the energy it needs if it can’t use the glucose in your blood properly.

The way Humulin N works

Humulin N contains the active drug isophane insulin human. This is a special type of insulin human made to release the drug slowly over time.

Insulin human is a copy of the insulin your pancreas makes naturally. So your body is able to use insulin human in the same way it uses natural insulin. (Insulin works by moving glucose from your bloodstream into your cells, where they use the sugar as energy.)

Insulin human is made using recombinant DNA technology. This means genetic material is combined in order to make the insulin.

Humulin N and children

Humulin N is approved to help manage blood sugar levels in children with type 1 or type 2 diabetes. Like the dosage for adults, the Humulin N dosage for children will be personalized based on their blood sugar goals and needs. Talk with your child’s doctor for more information.

Clinical studies have found Humulin N to be safe and effective for managing blood sugar levels in people with type 1 or type 2 diabetes.

American Diabetes Association guidelines for managing blood sugar in people with type 1 or type 2 diabetes recommend insulin human, including Humulin N, as a treatment option. Your doctor can help determine the most effective and safest treatment plan for your diabetes.

Before you use Humulin N, there’s some important information to keep in mind. The drug may not be a safe option for you if you have certain medical conditions or other factors that affect your health. Some of these are mentioned below.

If any of the following medical conditions or other health factors are relevant to you, talk with your doctor before using Humulin N:

  • if you have a history of liver or kidney problems
  • if you have heart failure and use a type of diabetes medication called a thiazolidinedione, such as pioglitazone (Actos) or rosiglitazone (Avandia)
  • if you take other prescription medications (especially other drugs to treat diabetes), over-the-counter medications, herbs, vitamins, or supplements
  • if you’re pregnant or thinking of becoming pregnant
  • if you’re breastfeeding or thinking of breastfeeding
  • if you’ve had an allergic reaction to Humulin N or any of its ingredients

How much Humulin N costs is based on several factors. These can include your prescribed treatment regimen, the insurance plan you have, the pharmacy you use, and your location. You’ll also need supplies such as needles or syringes. For estimates of how much Humulin N KwikPens and vials cost, see GoodRx.com.

Humulin N is a brand-name medication that isn’t available as a biosimilar. Brand-name drugs usually cost more than biosimilars.

There is another medication similar to Humulin N, called Novolin N. For more information on how Humulin N and Novolin N are alike and different, see this article.

Now that you’ve learned about Humulin N for diabetes, you may still have some questions. Talk with your doctor or pharmacist, who can advise you on whether Humulin N might be right for you.

Here are some other helpful references:

  • Drug comparison. To find out how Humulin N compares with Humulin R, read this article.
  • Information on diabetes. For more information on diabetes, see our list of diabetes articles.

Disclaimer: Medical News Today 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 other 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.