If you’re looking at treatment options for diabetes, your doctor might suggest Humulin N (isophane insulin human).

Humulin N is an over-the-counter medication that’s used to treat type 1 and type 2 diabetes in adults and children. The drug helps manage blood sugar levels. To learn more about diabetes, see the “What is diabetes?” section below.

The active ingredient in Humulin N is isophane insulin human, which is a biologic. Humulin N belongs to a group of drugs called intermediate-acting insulins.

Humulin N comes as a suspension (a type of liquid mixture). It’s available in vials and single-use, prefilled injection pens called KwikPens. You’ll give yourself Humulin N as an injection under your skin.

This article gives details on Humulin N and its use in treating diabetes. For more information about Humulin N, talk with your doctor or pharmacist.

Your doctor will explain how you should use Humulin N. They’ll also tell you how much to use and how often. Be sure to follow your doctor’s instructions.

Humulin N comes as a suspension (a type of liquid mixture). It’s available in two forms:

What is the typical dosage for Humulin N?

The typical dosage for Humulin N depends on a few factors. These include:

  • whether you have type 1 or type 2 diabetes
  • the form of Humulin N you use
  • your blood sugar levels
  • your weight
  • your eating habits
  • when and how often you exercise
  • other medications you take, including other types of insulin
  • other medical conditions you have

Your doctor will tell you exactly how much Humulin N to use for each dose.

How do you use Humulin N?

You’ll inject Humulin N under your skin. Your doctor will show you how to give yourself injections of Humulin N using insulin syringes or the Kwikpen. You can inject it into your belly, upper arm, thigh, or buttocks.

Be sure to inject Humulin N into a different area for each dose. For example, you can give each injection into your thigh, but make sure to use a different part of your thigh for each dose. This lowers your risk for reactions around your injection sites. (For details, see “What are the side effects of Humulin N?” section below.)

Detailed instructions for how to use Humulin N can be found in the drug’s prescribing information.

How often should I use Humulin N?

How often Humulin N is used can vary from person to person. Specifically, it depends on how often you need to use the drug to help manage your blood sugar levels. You might inject Humulin N two or more times a day. But be sure to follow the dosage instructions from your doctor.

Using Humulin N for diabetes (its only approved use) may cause side effects in some people. These side effects can be mild or severe.

The lists below include some of the main side effects that have been reported in people using Humulin N. For information about other possible side effects of the drug, talk with your doctor or pharmacist. You can also learn more from the Humulin N prescribing information.

What are Humulin N’s mild side effects?

Humulin N may cause mild side effects for some people.

Mild side effects that have been reported with Humulin N include:

  • swelling in your arms, feet, hands, or legs
  • reactions around your injection sites, such as itching, rash, and swelling
  • weight gain

In many cases, mild side effects from the drug can be temporary. Some side effects may be easy to manage, too. But if side effects last for a longer time, or if they bother you or become severe, talk with your doctor or pharmacist.

What are Humulin N’s serious side effects?

Serious side effects from Humulin N may occur. Low blood sugar is the most common serious side effect of all insulins. This includes Humulin N.

Other serious side effects that have been reported with Humulin N include a low level of potassium in your blood and allergic reaction.

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

Read on for answers to a few frequently asked questions about using Humulin N for diabetes.

Can I use Humulin N to treat my gestational diabetes?

Yes, Humulin N can be used to treat gestational diabetes.

Gestational diabetes is a type of diabetes that happens during pregnancy. The American Diabetes Association recommends insulins (such as Humulin N) to help manage blood sugar levels in pregnancy. This includes gestational diabetes.

If you have questions about using Humulin N to treat gestational diabetes, talk with your doctor. They can suggest the best treatment option for your condition.

What kind of insulin is Humulin N?

Humulin N is an intermediate-acting insulin. It’s considered “intermediate-acting” because it takes about 4 hours to start working after it’s injected.

Humulin N isn’t a type of regular insulin. Regular insulins are typically short-acting insulins, which take about 30 minutes to start working after they’re injected. Your pharmacist or doctor can give you details about this, if you like.

Diabetes is a condition that happens when your blood sugar level is too high.

Your body uses blood sugar as its main source of energy. Normally, your pancreas releases a hormone called insulin to help your body’s cells absorb blood sugar.

With type 1 diabetes, your pancreas doesn’t make enough insulin. With type 2 diabetes, your pancreas makes enough insulin, but your body can’t use the insulin effectively. Both conditions cause a high blood sugar level.

Over time, having a high blood sugar level can lead to severe problems. This includes heart disease and kidney disease.

What are the symptoms of diabetes?

Symptoms of diabetes can include:

Who can use Humulin N?

Humulin N is can be used by adults and children with type 1 and type 2 diabetes. The drug helps manage blood sugar levels.

Humulin N is used in adults and children with type 1 and type 2 diabetes. The drug helps manage blood sugar levels.

Diabetes is a condition that happens when your blood sugar level is too high. Normally, your pancreas releases a hormone called insulin to help your body’s cells absorb blood sugar.

But with diabetes, your body either doesn’t make enough insulin, or it can’t effectively use the insulin it makes.

How does Humulin N work?

Humulin N helps manage your blood sugar levels. It works by adding to or replacing the insulin your body makes naturally.

Humulin N lowers your blood sugar levels by:

  • helping your muscle cells and fat cells absorb sugar from your blood
  • keeping your liver from making more blood sugar
  • preventing your body from breaking down certain fats and proteins so that it can break down blood sugar instead

Studies have shown Humulin N is effective for managing blood sugar levels in people with type 1 and type 2 diabetes.

The American Diabetes Association recommends intermediate-acting insulins, such as Humulin N, for use in treating diabetes.

If you have questions about how effective Humulin N may be for treating your condition, talk with your doctor.

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 apply to you, talk with your doctor before using Humulin N.

Humulin N is available over-the-counter. You can purchase Humulin N without a prescription from your doctor. But keep in mind that your insurance plan may cover some of the cost for Humulin N if your doctor writes a prescription for it.

The price of Humulin N depends on several other factors. These can include your treatment plan, your insurance plan, the pharmacy you use, and your location. You may also need to buy other supplies, such as syringes and needles.

For estimates of how much Humulin N costs, visit GoodRx.com.

Humulin N is a brand-name biologic drug that’s not available as a biosimilar. (Biosimilars are like generic drugs. But unlike generics, which are made for nonbiologic drugs, biosimilars are made for biologic drugs.)

Talk with your doctor about using Humulin N for diabetes. They can help determine if it might be a good fit for you.

Here are some examples of questions you may want to ask your doctor:

  • Should I use Humulin N along with diet and exercise to help manage my blood sugar levels?
  • How often should I check my blood sugar levels while using Humulin N?
  • How will I know if Humulin N is working to treat my diabetes?

If you have type 2 diabetes and want helpful tips for managing your condition, sign up for Healthline’s diabetes newsletter.

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.