Canine Diabetes Wiki
Humulin S
R, Neutral by Eli Lilly
U40, U100 none
Action in dogs:
  • onset 10-30 minutes,
  • peak 1-5h,
  • duration 4-10h [1]
Line: Humulin
Also known as: Huminsulin Normal
Humulin CHumulin R, Humuline R
Humuline Regular, Humulin Regular
Humulina RegularHumulin ReliOn R
Umuline Rapide, Umuline Regular
Similar to: Insuman Rapid, Winthrop Rapid
Actrapid, Novolin R, ReliOn/Novolin R

Names of Lilly r-DNA/GE/GM insulins worldwide
Use and Handling:
Shelf Life: 24 months Type: soluble, clear
When Opened: 28 days room temp.
In Pen: 28 days room temp.
Notes: Protect from light and heat
Do Not Freeze,
May be used intravenously

Humulin S-a fast-acting, neutral, soluble insulin. Note package similarity of comparable insulin Insuman Rapid.

UK brand name for Lilly's short-acting r-DNA/GE/GM human insulin. [2][3][4][5]

The "S" in the product's name is an abbreviation for "soluble".

It's known in North America as Humulin R, [6][7] elsewhere as Huminsulin Normal, and can also be referred to as Toronto insulin instead of the R classification.

Both Novo Nordisk [8] and Aventis produce comparable insulins.

Novo's names for them are Actrapid [9][10][11] and Novolin R; Aventis' is Insuman Rapid [12][13] and Winthrop Rapid.

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


Human activity profile for r-DNA/GE/GM R (Regular)/Neutral insulin. See links for dog activity.

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. Insulins. North American Veterinary Conference Clinicians Brief (2006).
  2. Patient Information Leaflet-Humulin S. Eli Lilly.
  3. Humulin S Prescribing Information.
  4. Lilly EU/UK Product Sheet & Time Activity Profiles. Eli Lilly.
  5. Humulin S. Medguides UK.
  6. Humulin R patient leaflet. Eli Lilly.
  7. Humulin R Regular Human Insulin. Revolution Health.
  8. Novolin R. Revolution Health.
  9. Patient Information Leaflet-Actrapid. Novo Nordisk.
  10. Scientific Discussion-Actrapid. EMEA.
  11. Prescribing Novo Insulins.
  12. Patient information Leaflet-Insuman Rapid. Sanofi-Aventis.
  13. Prescribing Insuman Insulins.
  14. Humulin R patient leaflet. Eli Lilly.
  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
A1833110 HumilinLILLY Rtap DSC02818 Actrapid
Novolin R
Humulin R
Winthrop Rapid
Insuman Rapid