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,
Protaphan,  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]

Protaphane 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 patient leaflet. Eli Lilly.
  14. Humulin N NPH/Isophane Human Insulin. Revolution Health.
  15. Humulin I Prescribing Information.
  16. Patient Information 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 Doctor
  22. Hypurin Bovine Isophane patient information. 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