Insulin human isophane (NPH) (Injection)


Insulin Human Isophane (NPH) (IN-su-lin HUE-man EYE-soe-fane (NPH))

Treats diabetes mellitus.

Brand Name(s)

Humulin N, Humulin N Kwikpen, Humulin N Pen, Novolin N, ReliOn Humulin N, Relion Novolin N

When This Medicine Should Not Be Used

How to Use This Medicine


  • Your doctor will prescribe your exact dose and tell you how often it should be given. This medicine is given as a shot under your skin.
  • Use only the brand of medicine your doctor prescribed. Other brands may not work the same way.
  • You may be taught how to give your medicine at home. Make sure you understand all instructions before giving yourself an injection. Do not use more medicine or use it more often than your doctor tells you to.
  • This insulin usually starts to work about one and a half hours after it has been injected. The strongest effects are from 4 hours until about 12 hours after the injection. This insulin may keep working for as long as 18 to 24 hours after the injection, but it slowly works less and less. The way NPH insulin works for you might be different. You and your health caregiver must work together to know the best times for you to use your insulin.
  • This medicine comes as pre-filled insulin pen. Carefully read and follow the patient instructions on how to use it. This type of pen requires you to follow certain steps before you use the medicine. These steps can include preparing the pen, putting on a new needle, priming the pen, and setting your dose. You must follow these steps to make sure you receive the right dose of insulin.
  • You will be shown the body areas where this shot can be given. Use a different body area each time you give yourself a shot. Keep track of where you give each shot to make sure you rotate body areas.
  • This medicine is to be taken by using special syringes. Your doctor will tell you which type and brand of syringe to use. Do not share your needles or syringes with others.
  • Use a new needle and syringe each time you inject your medicine.
  • If you are using reusable syringes and needles, you must sterilize them before reusing. Follow the sterilizing directions given with your syringes.
  • Carefully follow your doctor's instructions about any special diet.
  • Your doctor may suggest that you follow an exercise program. You may also be taught to check your own blood sugar levels at home. Diet, exercise, medicine, and checking your blood sugar are all important to manage your diabetes.

If a dose is missed:

  • Call your doctor or pharmacist for instructions.

How to Store and Dispose of This Medicine

  • If you store this medicine at home, keep it in the refrigerator. Do not freeze.
  • Do not use insulin if it is past the expiration date stamped on the pen. Throw away any pen that is kept out of a refrigerator for longer than 2 weeks.
  • Throw away used needles in a hard, closed container that the needles cannot poke through. Keep this container away from children and pets.
  • Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any leftover medicine, containers, and other supplies. Throw away old medicine after the expiration date has passed.
  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Drugs and Foods to Avoid

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Make sure your doctor knows if you are using diabetes medicine that you take by mouth such as glipizide, glyburide, Actos®, Amaryl®, Avandia®, Glucophage®, or Glucotrol®.
  • Some medicines can affect the amount of insulin you need to use. Make sure your doctor knows about all other medicines you are using.
  • Do not drink alcohol while you are using this medicine.

Warnings While Using This Medicine

  • Make sure your doctor knows if you are pregnant or planning to become pregnant. Tell your doctor if you are breastfeeding.
  • Make sure your doctor knows if you have liver disease, kidney disease, or problems of the adrenal, thyroid, or pituitary gland.
  • Never share insulin pens or cartridges with others under any circumstances. It is not safe for one pen to be used for more than one person. Sharing needles or pens can result in transmission of hepatitis viruses, HIV, or other blood-borne illnesses.
  • Your doctor will check your progress and the effects of this medicine at regular visits. Keep all appointments.
  • This medicine may make you dizzy or drowsy. Avoid driving, using machines, or doing anything else that could be dangerous if you are not alert.
  • Your dose of insulin may change slightly with changes in your diet or physical activity. Your dose may also be changed while you are ill, pregnant, traveling, taking a new medicine, or exercising more than usual. Follow your doctor's instructions about making any changes in your insulin dose.

Possible Side Effects While Using This Medicine

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Blurred vision.
  • Fast or pounding heartbeat.
  • Lightheadedness or fainting.
  • Problems with speech, balance or walking.
  • Seizures, tremors, or shaking.
  • Trouble breathing.

If you notice these less serious side effects, talk with your doctor:

  • Depression or anxiety.
  • Feeling nervous or agitated.
  • Headache, or trouble sleeping or concentrating.
  • Increased sweating.
  • Increased thirst or appetite.
  • Mild skin rash.
  • Redness, pain, itching, or swelling under your skin where the shot is given.
  • Tingling in your hands, feet, lips, or tongue.

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Version Info

  • Last reviewed on 8/4/2014

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