Canine Diabetes Wiki
NPH/Isophane by Novo Nordisk
U40, U100 isophane
Action in dogs:
  • onset 0.5-3h,
  • peak 2-10h, [1]
  • duration 4-24h [2]
Line: Novolin
Also known as: Novolin N, Insulatard,
Protaphane,  ReliOn/Novolin NPH
Similar to: Humulin I, Huminsulin Basal, Humulin N, Humulin NPH, Humulina NPH, Humuline NPH, Humuline N, Umuline NPH, Humulin ReliOn N
Insuhuman Basal, Winthrop Basal
Insuman Basal, Isuhuman Basal

Names of Lilly r-DNA/GE/GM insulins worldwide
Use and Handling:
Shelf Life: 30 months Type: cloudy
When Opened: 6 weeks room temp.
In Pen: 6 weeks room temp.
Notes: Protect from light and heat
Do Not Freeze, Resuspend
Do not use if product does not re-suspend
Do not use intravenously [3]

Protaphan insulin in 3 ml pen cartridge.

Note that some countries have the brand name in U40 strength.

Another Novo Nordisk name for its NPH/isophane insulin. [4][5][6][7][8]

This type of insulin tends to have an onset of 2-4 hours, a peak action of 4-10 hours, and a total duration of 10-20 hours, in humans.

It is a neutral suspension of isophane insulin crystals. [9][10]

Those in North America know it as Novolin N; [11] others call it Insulatard.

It is an intermediate-acting insulin [12] with more than one company producing this type.

Eli Lilly calls theirs Umuline NPH, Humuline NPH, Huminsulin Basal, Humulina NPH, Humulin N [13][14] and Humulin I, [15][16] while Aventis has its Insuman Basal [17][18] and Winthrop Basal.

Specifications of NPH/isophane insulin[]

British National Formulary [19] defines this type as: A sterile suspension bovine or porcine or of human insulin in the form of a complex obtained by the addition of protamine sulphate or another suitable protamine.

British Pharmacoepia and United States Pharmacopia definitions: [20]

Isophane Insulin

Sterile buffered suspension of insulin in the form of a complex obtained by addition of suitable protamine. Prepared from crystalline insulin. pH 6.9 - 7.5 iso-osmotic with blood. Contains for each 100 units of insulin, 300 - 600 g protamine sulphate and not more than 40 g zinc, a suitable bactericide and sodium phosphate as buffering agent.

USP specification: Sterile suspension of zinc insulin crystalline and protamine sulphate in buffered water for injection. Solid phase contain crystals of insulin protamine and zinc; 40, 80, 100 units/ml. Contains glycerol, metacresol, phenol sodium phosphate and zinc.

NPH/isophane insulins[]

The following commercial insulins are all generically NPH insulins:

Other commonly used names are:

  • NPH insulin, NPH
  • isophane insulin


  1. Insulins. North American Veterinary Conference (2005).
  2. Ruchinsky, Renee, et. al. (2010). Diabetes Management Guidelines for Dogs and Cats-page 7. American Animal Hospital Association.
  3. Maddison, Jill E.,Page, Stephen W.,Church, David B. (2008). Small Animal Clinical Pharmacology. Saunders Ltd..
  4. Scientific Discussions-Protaphane. EMEA.
  5. Protaphane. APP Online Guide.
  6. Protaphane. Novo Nordisk Australia.
  7. Prescribing Novo Insulins.
  8. Information on Protophane. Novo Nordisk.
  9. Scientific Discussion-Insulatard. EMEA.
  10. Patient Information Leaflet-Insulatard. Novo Nordisk.
  11. Novolin N. Revolution Health.
  12. Insulin. Diabetes New Zealand.
  13. Humulin N. Eli Lilly.
  14. Humulin N NPH/Isophane Human Insulin. Revolution Health.
  15. Humulin I Prescribing Information.
  16. Patient Infrmation Leaflet-Humulin I. Eli Lilly.
  17. Patient Information Leaflet-Insuman Basal. Sanofi-Aventis.
  18. Insuman Prescribing Information.
  19. British National Formulary-Isophane/NPH Insulin Definition. InChem.
  20. British Pharmacoepia (BP) & United States Pharmacoepia (USP)-Isophane/NPH Insulin Defined. InChem.
  21. Hypurin Bovine Isophane Patient Information. Net
  22. Hypurin Bovine Isophane. Wockhardt UK.
  23. Prescribing Bovine Insulin.
  24. Response to Withdrawal of Novo Porcine Insulins. CP/Wockhardt UK.
  25. Prescribing Porcine Insulin.
  26. Response to Withdrawal of Novo Porcine Insulins. CP/Wockhardt UK.
  27. Prescribing Novo Animal Insulin.
  28. Patient Information Leaflet-Pork Insulatard. Novo Nordisk.

More information[]

Related Pages
21938f Humulin n NVN34740 72167 5 DSC02817 Insulatard Protaphan2
Humulin I
Humulin N
Novolin N
Insuman Basal