Home/Medicines/Insulin, NPH (Isophane)

Insulin, NPH (Isophane)

Prescription

Intermediate-Acting Insulin

Last reviewed 21 Apr 2026 · PetCare.AI Editorial Team

Species

Dog, Cat

Brands

3 available

Interactions

1 documented

Formulations

Mechanism of action

Crystalline suspension of insulin complexed with protamine, creating depot that slowly dissociates after SQ injection. Provides intermediate duration (8–14h dogs; 4–12h cats) with moderate peak activity.

At a glance

Class

Intermediate-Acting Insulin

Schedule

Prescription

Storage

Refrigerate 2–8°C; in-use at room temperature up to 42 days (Vetsulin 28 days); gently roll/shake before use; do not freeze

Dosing

🐕

Dog

Standard insulin for canine diabetes management

Dose

0.25–0.5 U/kg

Route

Frequency

q12h

🐈

Cat

Used for feline diabetes but glargine preferred (higher remission rates)

Dose

0.25–0.5 U/kg

Route

Frequency

q12h

Educational reference only

This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Formulations

💊

Other — 2

Strength

—

Strength

—

Storage

Refrigerate 2–8°C; in-use at room temperature up to 42 days (Vetsulin 28 days); gently roll/shake before use; do not freeze

Safety

Monitoring parameters

Blood glucose curves at 7 and 14 days then monthly until stableFructosamine q2–4 weeksBody weightWater intakeUrine glucose

Educational reference only

Interactions

Major — 1

Prednisolone

major

Corticosteroid-induced insulin resistance destabilizes diabetic control.

Management: Closely monitor blood glucose. Significant insulin dose adjustments likely needed. Hypoglycemia risk when steroid discontinued.

Educational reference only

Brands

Other markets

Humulin N

Novolin N

Vetsulin/Caninsulin (porcine lente)

FAQs

Frequently asked questions

›What is Insulin, NPH (Isophane)?

Insulin, NPH (Isophane) is a intermediate-acting insulin used in pets. Crystalline suspension of insulin complexed with protamine, creating depot that slowly dissociates after SQ injection. Provides intermediate duration (8–14h dogs; 4–12h cats) with moderate peak activity.

›What is Insulin, NPH (Isophane) used for in pets?

Insulin, NPH (Isophane) is used in veterinary medicine for: Standard insulin for canine diabetes management; Used for feline diabetes but glargine preferred (higher remission rates).

›What is the Insulin, NPH (Isophane) dose for dogs?

For dogs, Insulin, NPH (Isophane) is typically dosed as follows — Standard insulin for canine diabetes management: 0.25–0.5 U/kg SQ q12h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.

›What is the Insulin, NPH (Isophane) dose for cats?

For cats, Insulin, NPH (Isophane) is typically dosed as follows — Used for feline diabetes but glargine preferred (higher remission rates): 0.25–0.5 U/kg SQ q12h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.

›Does Insulin, NPH (Isophane) need a prescription?

Yes. Insulin, NPH (Isophane) is a prescription medication and should only be administered under veterinary supervision.

Educational reference only

References

The PetCare.AI drug reference is built from 13 authoritative sources cited across 580 drug monographs.

Textbooks & handbooks — 5

Plumb's Veterinary Drug Handbook
Withrow & MacEwen's Small Animal Clinical Oncology
Merck Veterinary Manual
NRC Nutrient Requirements of Dogs and Cats
Veterinary Pharmacology and Therapeutics (Riviere & Papich)

Clinical guidelines & consensus — 4

ASPCA Animal Poison Control Center Guidelines
AAHA Diabetes Management Guidelines
ASPCA Poison Control Guidelines
RECOVER CPR Guidelines

Journals & peer-reviewed studies — 2

EPIC Study (J Vet Intern Med 2016)
JVIM FAT CAT Study

Regulatory & approvals — 1

CDSCO Veterinary Drug Approval Registry (1969–2026)

Databases — 1

Washington State University VCPL MDR1 Database

Related medicines

Other medicines in the same class (Intermediate-Acting Insulin).

Insulin (NPH / Isophane)

Exogenous insulin that binds to insulin receptors, facilitating glucose uptake into cells, glycogen synthesis, and protein synthesis while inhibiting gluconeogenesis and lipolysis

dogcat