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

Names of Lilly r-DNA/GE/GM insulins worldwide
Use and Handling:
Shelf Life: 24 months Type: soluble, clear
When Opened: 4 weeks, below 25C
In Pen: 4 weeks, below 25C
Notes: Protect from light and heat
Do Not Freeze,
May be used intravenously

Insuman insulins in pen cartridge form.

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

Winthrop Rapid is another of Aventis' brand names for its r-DNA/GE/GM short-acting insulin. [2] It is identical to the Aventis Insuman line of products. [3][4][5]

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

Other brands of the same type of insulin are: Huminsulin Normal, Humulin R [7] and Humulin S. [8][9][10] by Eli Lilly--Actrapid [11][12] and Novolin R by Novo Nordisk [13].

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 [14] in R/neutral; it's totally dissolved and soluble, meaning it can safely be used intravenously.[15]

The very small insulin particles in semilente insulin are suspended by zinc. [14] Semilente is cloudy, has an acetate buffer and cannot be used intravenously.

R/Neutral insulin cannot be reliably mixed with Lente or Ultralente insulins. [16][17] Semilente can; the ratio of 3 parts semilente insulin to 7 parts ultralente insulin produces Lente insulin. [14]

R/Neutral Insulins[]


  1. Insulins. North American Veterinary Conference Clinicians Brief (2006).
  2. Patient Information Leaflet-Insuman Rapid. Sanofi-Aventis.
  3. Aventis Poster-Insuman & Lantus Insulins. Sanofi-Aventis.
  4. Insulin Winthrop. EMEA.
  5. Scientific Discussion-Insuman. EMEA.
  6. Humulin R. Eli Lilly.
  7. Humulin R Regular Human Insulin. Revolution Health.
  8. Patient information Leaflet-Humulin S. Eli Lilly.
  9. Humulin S Prescribing Information.
  10. Lilly EU/UK Product Sheer & Time Activity Profiles. Eli Lilly.
  11. Scientific Discussion-Actrapid. EMEA.
  12. Prescribing Novo Insulins.
  13. Novolin R. Revolution Health.
  14. 14.0 14.1 14.2 DeRuiter, Jack. Insulin Preparations-Regular Insulin. Auburn University. Cite error: Invalid <ref> tag; name "DeRuiter" defined multiple times with different content Cite error: Invalid <ref> tag; name "DeRuiter" defined multiple times with different content
  15. Maddison, Jill E.,Page, Stephen W.,Church, David B. (2008). Small Animal Clinical Pharmacology. Saunders Ltd..
  16. Deckert, T. (1980). Intermediate-Acting Insulin Preparations: NPH (Isophane) & Lente. Diabetes Care.
    Note--in 1980, there were no r-DNA/GE/GM insulins
  17. Resource Guide. American Diabetes Association (2005).

More Information[]

Related Pages
Rtap HumilinLILLY 21944f DSC02818 Actrapid
Humulin ReliOn R
Humulin R
Humulin S
Insuman Rapid