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

Names of Lilly r-DNA/GE/GM insulins worldwide
Use and Handling:
Shelf Life: 24 months Type: cloudy
When Opened: 28 days room temp.
In Pen: 28 days 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]

NPH insulin time activity profile.

Humulin ReliOn N is Eli Lilly's brand name for their NPH-based insulin product. [4] This insulin is also known as Umuline NPH, Humuline NPH, Huminsulin Basal and Humulina NPH. Novo-Nordisk had been producing the ReliOn brand insulins since their inception in 2000, but in October 2010, WalMart signed with Eli Lilly for their production.[5][6] The ReliOn insulins are still offered in the same types, R, NPH, and 70/30 mix, but they are produced by Eli Lilly and branded as Humulin/ReliOn insulins. [7][8][9] Novolin insulins have NOT been discontinued; these insulins are available as Novolin N, Novolin R, and Novolin 70/30. Only the ReliOn/Novolin branded insulins have been phased out.

It is an intermediate-acting insulin.

Like all other isophane/protamine suspended insulins [10], it is a crystalline suspension with protamine.

NPH (Isophane) insulin was originally developed by Novo Nordisk labs in 1946, as an insulin with intermediate action.

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.

Humulin N or generic NPH, and their Novo Nordisk competitor Novolin N [11] aka Insulatard [12][13][14] and aka Protaphane, [15] are available in the USA with no prescription.

In the UK, Humulin N is known as Humulin I ("I" standing for its isophane suspension.); [16][17][18] elsewhere it's called Huminsulin Basal. Aventis also makes two similar NPH insulins called Insuman Basal [19][20] and Winthrop Basal.

Specifications of NPH/isophane insulin[]

British National Formulary [21] 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: [21]

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. Humulin N NPH/Isophane Human Insulin. Revolution Health.
  5. A Change to ReliOn Insulin. ReliOn.
  6. Low Cost Insulin Available through major retailer. Diabetes Health (1 December 2000).
  7. Wal-Mart Changes Insulin Partners. Wall Street Journal (22 June 2010).
  8. Wal-Mart Press Release (22 June 2010).
  9. ReliOn insulins. ReliOn.
  10. Humulin N patient leaflet. Eli Lilly.
  11. Novolin N. Revolution Health.
  12. Patient Information Leaflet-Insulatard. Novo Nordisk.
  13. Prescribing Novo Insulins.
  14. Scientific Discussion-Insulatard. EMEA.
  15. Scientific Discussion-Protaphane. EMEA.
  16. Humulin I Prescribing Information.
  17. Patient Information Leaflet-Humulin I. Eli Lilly.
  18. Lilly EU/UK Product Sheet & Time Activity Profiles. Eli Lilly.
  19. Patient Information Leaflet-Insuman Basal. Sanofi-Aventis.
  20. Insuman Prescribing Information.
  21. 21.0 21.1 British National Formulary-Isophane/NPH Insulin Definition. InChem. Cite error: Invalid <ref> tag; name "InChem" defined multiple times with different content
  22. Hypurin Bovine Isophane Patient Information. Net Doctor uk..
  23. Hypurin Bovine Isophane. Wockhardt UK.
  24. Prescribing Bovine Insulin.
  25. 25.0 25.1 Response to Withdrawal of Novo Porcine Insulins. CP/Wockhardt UK.
  26. Prescribing Porcine Insulin.
  27. Prescribing Novo Animal Insulin.
  28. Patient Information Leaflet-Pork Insulatard. Novo Nordisk.

More Information[]

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