Iletin I NPH
NPH/Isophane by Eli Lilly
intermediate-acting Bovine
U100 isophane
Line Iletin
Also known as beef NPH, beef isophane
Similar to  
Action in cats  
  • onset Xh,
  • peak Xh
  • duration Xh
Action in dogs  
  • onset within 2h,
  • peak 6-12h,
  • duration 18-24h
Use and Handling
Type cloudy
Shelf Life 24 months
When opened 28 days room temp.
In pen N/A

A pure beef NPH/isophane suspended insulin formerly made by Eli Lilly.

Like all other isophane/protamine suspended insulins[1], it was a crystalline suspension with protamine and zinc[2].

The currently marketed equivalent is Hypurin Bovine Isophane[3][4][5], made by CP Pharma[6].


  1. US FDA-Humulin N
  2. Discontinuation of Iletin I Beef/Pork line of Insulins. Iletin I N is shown at middle.
  3. Hypurin Bovine Isophane Patient Information
  4. Electronic Medicines Compendium (EMC) UK-Hypurin Bovine Isophane
  5. Hypurin Bovine Isophane Beef NPH Insulin
  6. Prescribing Bovine Insulin
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