Medicine & USMLE

Intermediate Acting Insulin

Diabetes Drugs
  1. Insulin Overview
  2. Rapid Acting Insulin
  3. Short Acting Insulin
  4. Intermediate Acting Insulin
  5. Long Acting Insulin
  6. Metformin
  7. Sulfonylureas
  8. Meglitinides
  9. Thiazolidinediones (TZDs)
  10. DPP-4 Inhibitors
  11. Incretin Mimetics
  12. SGLT2 Inhibitors
  13. Alpha Glucosidase Inhibitors
  14. Pramlintide


Intermediate-acting insulin is a mid-range insulin that takes anywhere from 4-12 hours to reach peak insulin levels in the blood. The only drug name you need to know is NPH insulin. Before administering NPH insulin, gently roll the vial between the palms of your hand to mix the suspension - do not shake the vial. NPH insulin has a cloudy appearance. Lastly, when mixing NPH insulin with regular insulin, be sure to draw the NPH insulin into your syringe last.

Key Points

  • Intermediate Acting Insulin
    • Drug Names
      • NPH (Humulin N, Novolin N)
    • Onset, Peak, Duration
      • Onset = 1-2 hours after administration
      • Peak = 4-12 hours after administration
        • Peak time is the most important timing to know, since it’s at the peak that patients are most likely to experience hypoglycemia
      • Duration = 12-18 hours after administration
    • Administration
      • When mixing insulin types, draw NPH insulin last
        • NPH insulin should be drawn into the syringe LAST, after regular insulin
        • “RN” - regular before NPH
      • Cloudy appearance
        • All other insulin types are clear, NPH insulin is the only insulin that has a cloudy appearance
      • Roll in palm to mix suspension, do not shake
        • Shaking the bottle can introduce air into the solution and alter the dosage when drawn into a syringe
      • Usually given twice daily