Diabetes in Pets
Insuvet Lente
Lente by Pfizer Animal Health
intermediate-acting Bovine
U100 Zinc
Line Insuvet
Also known as beef lente
Similar to  
Action in cats  
  • onset 1-3h[1],
  • peak 4-6h
  • duration 8-10h
Action in dogs  
  • onset 1-3 h,
  • peak 6-12h,
  • duration 18-28h
Use and Handling
Type cloudy
Shelf Life 36 months
When opened 28 days
In pen N/A

Pfizer Animal Health UK produces bovine insulins for veterinary use under the brand name Insuvet. This is their U100, intermediate-acting lente[2] insulin[3][4][5].

What Lente Is Not

No Lente-type insulin regardless of species can contain any NPH/isophane insulin[6] or any R/Neutral insulin[7][8].

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[9].

The zinc suspension of Lente-type insulin binds R/Neutral, causing the short-acting insulin to slow, losing its short-acting effect[10].

Technical details

The official NOAH (National Office of Animal Health)[11] description of Insuvet Lente is that it is a highly purified bovine Zinc suspension insulin as per British Pharmacopeia (BP). The "mixed" tag refers to the 30% semilente, 70% ultralente composition of all lente insulins. It is U100 and presented in 10ml vials. The insulin[12] has a shelf life of 3 years.

Usage and handling

Insuvet Lente[13]is classed as being a medium to long duration insulin given subcutaneously. Onset is 1-3 hours after injection, with a peak at 6-12 hours and a total duration of 18-28 hours.

Feline insulin compared with Bovine, Human, & Porcine versions. Up to 4 amino acids differ. The closest match is bovine with only one amino acid difference; the lease close is human with four amino acid differences.

Dosage information for Insuvet Lente[14] can be found here. To be given subcutaneously[15]only. Store at 2-8 C[16] at 2-8 C. Insuvet Lente requires rolling and should not be used if product does not re-suspend. Do not freeze. Vials are to be used within 28 days of their first use.

Comparable to CP Pharma's Hypurin Bovine Lente[17], but is only approved for veterinary use. It is also comparable to Lilly's discontinued Iletin I Lente.

Combining Lente Family Insulins

None of the Lente family of insulins (semilente, Lente, Ultralente) can be combined with[18] 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[19].

Keeping the phenol preservatives in mind, all protamine-suspended insulin mixes would be "off limits" regarding same syringe mixing with any Lente-type insulins[20].

Insulin manufacturers[21] 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[22][23][24][25].

Best Pet Pharmacy stocks this for sale in the UK.


  1. Petsulin Lente Page 9 Note re:shorter feline duration
  2. Photo-Insuvet Lente vial and carton
  3. Hypurin Bovine Lente Patient Information
  4. Electronic Medicines Compendium (EMC) UK-Hypurin Bovine Lente
  5. Prescribing Bovine Insulin
  6. Combining Lente-type Insulins with Phenol-Preserved Insulins
  7. Lente Zinc Suspension Causes Loss Of R/Neutral Short-Acting Effect
  8. Resource Guide 2005-American Diabetes Association
  9. Lente-Type Insulins & NPH/Isophane Insulins-A Bad Combination
  10. Intermediate-Acting Insulin Preparations: NPH (Isophane) & Lente Diabetes Care-1980
    Note--in 1980, there was only beef Lente-type insulin--no pork or r-DNA/GE/GMLente insulins
  11. NOAH Compendium UK-Insuvet
  12. Medications
  13. NOAH Compendium-UK-Insuvet-Uses
  14. NOAH Compendium-UK-Insuvet-Dosage & Administration
  15. NOAH Compendium-UK-Insuvet-Contraindications/Warnings
  16. NOAH Compendium-UK-Insuvet-Pharmaceutical information
  17. Hypurin Bovine Lente-Lente Beef Insulin Remedyfind.com
  18. Phenol Preservatives & Lente-type Insulins--A Bad Combination
  19. RxEd.org-Insulin Therapy-Mixing Precautions
  20. RxEd.org-Insulin Therapy-Mixing Precautions
  21. Insulin Producers vs Doctors Re:Combining R/Neutral & Lente-type Insulins
  22. Availability of Soluble (R/Neutral) Insulin in Mixed Preparations of Crystalline (Lente) & Ultralente GE Insulins-Clinical Therapeutics-1991
  23. Absorption Kinetics & Action Profiles-Single Subcutaneous Administration of Human Soluble (R/Neutral) & Lente Insulin-Diabetes Care-1987
  24. Delayed Onset of Action of Soluble (R/Neutral) Insulin After Premixing With Lente Insulin Diabetes Research & Clinical Practice-1983
  25. RxEd.org-Insulin Therapy-Mixing Precautions