Canine Diabetes Wiki
Iletin II R
R, Neutral by Eli Lilly
U100 none
Action in dogs:
  • onset 30-60 minutes,
  • peak 2-4h,
  • duration 6-8h
Line: Iletin
Also known as: Pork R, pork neutral
Similar to: Betasint Porcine Corriente
Hypurin Porcine Neutral, [1] Hypurin Pork Regular
Maxirapid CHO, Pork Actrapid, Leo Neutral [2]
Use and Handling:
Shelf Life: 24 months Type: soluble, clear
When Opened: 28 days room temp.
In Pen: N/A
Notes: Protect from light and heat
Do Not Freeze,
May be used intravenously
May be used intramuscularly
Iletin II R

Iletin II R-pork R/Neutral insulin.

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

North American brand name for Eli Lilly's now discontinued [3][4][5] 100% U100 porcine R/neutral, soluble insulin.

Like all R or neutral insulins, nothing is added (suspensions) to alter the insulin's action or speed. [6]

Novo Nordisk produced a similar Pork Actrapid, [7][8] but discontinued it at the end of December 2007. [9]

CP Pharma--Hypurin Porcine Neutral [10][11][12][13], Beta Laboratorios--Betasint Porcine Corriente and Polfa Tarchomin--Maxirapid CHO are now the only producers.


Canine insulin compared with Bovine, Human, & Porcine versions. Up to 2 amino acids differ. Canine and porcine are identical [14].

A short-acting, soluble, non-suspended insulin produced from r-DNA/GE/GM, bovine, or porcine sources. From 1921 to the 1930's when PZI was developed, R was the only kind of insulin available.

While both R/neutral and semilente insulins are considered fast-acting, they differ in a few ways. As above, there's no suspension or buffer [15] in R/neutral; it's totally dissolved and soluble, meaning it can safely be used intravenously. [16]

The very small insulin particles in semilente insulin are suspended by zinc. [15]. Semilente is cloudy, has an acetate buffer and cannot be used intravenously

R/Neutral insulin cannot be reliably mixed with Lente or Ultralente insulins. [17][18] Semilente can; the ratio of 3 parts semilente insulin to 7 parts ultralente insulin produces Lente insulin. [15]

R/Neutral Insulins[]


  1. Response to Withdrawal of Novo Porcine Insulin Range. CP/Wockhardt UK.
  2. Montgomery, DAD. Modern Insulin and Insulin Therapy. Royal Victoria Hospital-Belfast.
  3. Lilly Discontinues Iletin II R & Iletin II N. US Food and Drug Administration (July 2005).
  4. Iletin II R carton photo.
  5. Iletin II R Discontinuation Sheet. Eli Lilly.
  6. Humulin R patient information leaflet. Eli Lilly.
  7. Pork Actrapid Patient Information. Net Doctor uk.
  8. Patient Information Leaflet-Pork Actrapid. Novo Nordisk.
  9. Pork Actrapid Discontinuation Notice. Novo Nordisk.
  10. Hypurin Porcine Neutral. Wockhardt UK.
  11. Prescribing Porcine Insulin.
  12. Hypurin Porcine Neutral Patient Information. Net Doctor uk.
  13. Prescribing Novo Animal Insulin.
  14. Caninsulin-Product Information. Intervet.
  15. 15.0 15.1 15.2 DeRuiter, Jack. Insulin Preparations-Regular Insulin. Auburn University. Cite error: Invalid <ref> tag; name "Auburn" defined multiple times with different content Cite error: Invalid <ref> tag; name "Auburn" defined multiple times with different content
  16. Maddison, Jill E.,Page, Stephen W.,Church, David B. (2008). Small Animal Clinical Pharmacology. Saunders Ltd..
  17. Deckert, T. (1980). Intermediate-Acting Insulin Preparations: NPH (Isophane) & Lente. Diabetes Care.
    Note--in 1980, there were no r-DNA/GE/GM insulins
  18. Resource Guide. American Diabetes Association (2005).

More Information[]

Related pages
Hypurin pork r
Pork Actrapid
Insulinum Maxrapid 400px
Betasint Porcine Corriente
Hypurin Porcine Neutral
Pork Actrapid
Maxirapid CHO