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Insulin NPH

Brand names: Humulin N, Novolin N, Humulin 70/30, Novolin 70/30

NPH insulin is a cloudy, intermediate-acting insulin, often taken twice a day. Some versions are sold over the counter at lower cost.

Brand namesHumulin N, Novolin N, Humulin 70/30, Novolin 70/30
Type of medicineIntermediate-acting insulin
Prescription?Prescription
ImportantThis page is general information, not a prescription. Don't start, stop, or change a medicine without talking to your provider or pharmacist.

Overview

It peaks several hours after a dose, so meal timing matters. 70/30 mixes include fast-acting insulin.

What it's used for

  • Type 1 and type 2 diabetes
  • Diabetes in pregnancy

How to take it

  • Gently roll the vial or pen until evenly cloudy before each dose; don't shake hard.
  • Follow your schedule for meals and snacks.
  • Rotate injection spots.

Your dose depends on your health and other medicines. Always follow your prescription label, and ask your pharmacist if anything is unclear.

Side effects

Common side effects

  • Low blood sugar
  • Weight gain
  • Injection site reactions
Call 911Severe low blood sugar: confusion, seizure, or passing out. Use glucagon if you have it, then call 911.
Call your provider todayLow blood sugar during the night (nightmares, sweating, morning headache)

Warnings

  • Over-the-counter insulin should still be used with a provider's plan.

Other medicines, foods, and alcohol

  • Other diabetes medicines add to low blood sugar risk.
  • Beta blockers can hide signs of low blood sugar.
  • Alcohol can cause low blood sugar.

Tell your provider and pharmacist about every medicine, vitamin, and supplement you take.

Pregnancy and breastfeeding

Commonly used in pregnancy.

Missed doses, overdose, and storage

If you miss a dose

Check your blood sugar and follow the plan your provider gave you. Don't double up.

If someone takes too much

Call Poison Control at 1-800-222-1222 or get help online at poison.org. Call 911 if the person collapses, has a seizure, has trouble breathing, or can't be woken.

Storing it

Keep unopened pens and vials in the refrigerator (don't freeze). Once opened, follow the label for how long it lasts at room temperature.

Conditions it's used for

Sources

Last updated 2026-11-13.