Canine Diabetes Wiki
Humulin I
NPH/Isophane by Eli Lilly
U40, U100 isophane
Action in dogs:
  • onset 0.5-3h,
  • peak 2-10h, [1]
  • duration 4-24h [2]
Line: Humulin
Also known as: Humulin N, Huminsulin Basal, Humulin NPH, Humulina NPH, Humuline N, Humuline NPH, Umuline NPH Humulin ReliOn N
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]

Humulin I-an intermediate-acting NPH/Isophane insulin. Note the similar packaging for comparable insulin Insuman Basal.

This is the Euro name for Lilly's isophane-suspension insulin [4]--the "I" an abbreviation for isophane. [5][6]

Lilly makes the same insulin known as Humulin N, [7] in North America [8] Humulina NPH, Umuline NPH, Humuline NPH, and Huminsulin Basal.

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

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.

Novo Nordisk also has their Novolin N, [9] Protaphane and Insulatard [10][11][12][13] while Aventis has their Insuman Basal [14][15] and Winthrop Basal.

Specifications of NPH/isophane insulin[]

British National Formulary [16] 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: [16]

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


More Information[]

Related Pages
Humulin n NPHtap NVN34740 72167 5 DSC02817 Insulatard Protaphan2
Humulin N
Humulin ReliOn N
Novolin N
Insuman Basal