Canine Diabetes Wiki
Ultralente by Novo Nordisk
U40, U100 Zinc
Action in dogs:
  • onset 2-10h,
  • peak 6-24h,
  • duration 14-24h
Line: Novo
Also known as: Novolin U
Similar to: Huminsulin Ultralong, Humulin U
Humulin UL, Humulin Ultralenta
Humulin Ultralente, Humulin Zn, Umuline Zinc
Humuline Ultralong, Humulina Ultralenta

Names of Lilly r-DNA/GE/GM insulins worldwide
Use and Handling:
Shelf Life: 30 months Type: cloudy
When Opened: 6 weeks room temp.
In Pen: N/A
Notes: Protect from light and heat
Do Not Freeze, Resuspend
Do not use if product does not re-suspend
Do not use intravenously [1]
store at 2-8C

Ultratard vial.

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

This is the name Novo Nordisk gave its Ultralente [2] insulin for the Euro market; [3][4][5] in North America when it was still produced, it was called Novolin U.

Eli Lilly also produced Ultralente insulins under some different names: Humulin U [6] Umuline Zinc, Humulina Ultralenta, Humuline Ultralong, and Humulin Zn. [7][8]

It was a crystalline-suspended insulin. [9][10] This is a long-acting insulin.

What Ultralente Is Not[]

No Lente-type insulin regardless of species can contain any NPH/isophane insulin [11] or any R/Neutral insulin.[12][13]

Both are chemically impossible: the phenol preservative present in NPH/isophane alters the action of Lente-type insulins, creating a mixture with an approximate action of R/Neutral. [14][15]

The zinc suspension of Lente-type insulin binds R/Neutral, causing the short-acting insulin to slow, losing its short-acting effect. [16][17]

Before the invention of VetPen, Lente-type insulins could not be dispensed in pen or cartridge form because the glass ball formerly used to mix the insulin in these devices shattered the Lente crystals.[18]

Combining Lente Family Insulins[]

None of the Lente family of insulins (semilente, Lente, Ultralente) can be combined with [19] NPH/isophane insulins. The phenol preservatives present in NPH-type insulins alters the Lente-types to the point where they become a close approximation of R/neutral, with regard to action. [20][21]

Keeping the phenol preservatives in mind, all protamine-suspended insulin mixes would be "off limits" regarding same syringe mixing with any Lente-type insulins. [21]

Insulin manufacturers [22] indicate that R/neutral and semilente, Lente, ultralente insulins are able to be combined in the same syringe, but only just before injection. In pre-filled syringes, the zinc suspension of the Lente-type insulins binds the R/neutral, causing it to lose its short-acting effect. Various studies have documented this, and some doctors advise against using R/neutral in the same syringe with the Lente family of insulins. [23][24][25][21]

Trade names:

The Novo insulins, Novolin U and Ultratard, were available slightly longer in Europe. [4]

From the announcement: Monotard and Ultratard will not be available in the UK after February 2006. The discontinuation of these insulins was initially announced in September 2004. Initially the discontinuation was scheduled for February 2006, however this date has now been brought forward to October 2005.


  1. Maddison, Jill E.,Page, Stephen W.,Church, David B. (2008). Small Animal Clinical Pharmacology. Saunders Ltd..
  2. Definition of Ultralente Insulin. Merck Manual.
  3. Prescribing Novo Insulins.
  4. 4.0 4.1 Monotard/Ultratard Discontinuation. Diabetes UK (July 2005). Cite error: Invalid <ref> tag; name "UK" defined multiple times with different content
  5. Information on Ultratard. Novo Nordisk.
  6. Discontinuation Notice. US Food and Drug Administration (July 2005).
  7. Humulin Zn Discontinuation. Diabetes UK (July 2004).
  8. Lilly EU/UK Product Sheet & Time Activity Profiles. Eli Lilly.
  9. Scientific Discussion-Ultratard. EMEA.
  10. Dumitriu, Severian (2001). Polymeric Biomaterials, Revised and Expanded 1104. CRC Press.
  11. Combining Lente-type Insulins with Phenol-Preserved Insulins. National Federation for the Blind.
  12. Lente Zinc Suspension Causes Loss Of R/Neutral Short-Acting Effect.
  13. Huffman DM, Garber AJ. (1991). Availability of Soluble (R/Neutral) Insulin in Mixed Preparations With Crystalline (Lente) & Ultralente GE Insulin. Clinical Therapeutics.
  14. Lente-Type Insulins & NPH/Isophane Insulins-A Bad Combination. National Federation for the Blind.
  15. Havlik I, Galasko G, Alberts E, Furman KI, Seftel HC. (1988). Solubility Changes on Mixing Short- and Long-acting Insulin Preparations. South African Medical Journal.
  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).
  18. Hanas, Ragnar (1999). Insulin-Dependent Diabetes-Page 10. ChildrenWithDiabetes.
  19. Phenol Preservatives & Lente-type Insulins--A Bad Combination. National Federation for the Blind.
  20. Lente-Type Insulins & NPH/Isophane Insulins-A Bad Combination. National Federation for the Blind.
  21. 21.0 21.1 21.2 Insulin Therapy-Mixing Precautions. Cite error: Invalid <ref> tag; name "Rx" defined multiple times with different content
  22. Insulin Producers vs Doctors Re:Combining R/Neutral & Lente-type Insulins.
  23. name=HuffmanHuffman DM, Garber AJ.. Availability of Soluble (R/Neutral) Insulin in Mixed Preparations of Crystalline (Lente) & Ultralente GE Insulins. Clinical Therapeutics.
  24. Bilo HJ, Heine RJ, Sikkenk AC, van der Meer J, van der Veen EA. (1987). Absorption Kinetics & Action Profiles-Single Subcutaneous Administration of Human Soluble (R/Neutral) & Lente Insulin. Diabetes Care.
  25. Heine RJ, Sikkenk AC, Eizenga WH, van der Veen EA. (1983). Delayed Onset of Action of Soluble (R/Neutral) Insulin After Premixing With Lente Insulin Diabetes. Research & Clinical Practice.
  26. Discussion of differences between r-DNA Ultralente and beef Ultralente. Free Patents Online.
  27. Insulin Preparations-UK (1976).

More Information[]

Related pages
Human Activity Profiles Various Insulins
Umuline Zinc
Novolin U
Humulin U
Humulin Zn