Home/Medicines/Insulin (NPH / Isophane)
All medicines

Insulin (NPH / Isophane)

Prescription
Intermediate-acting insulin (isophane suspension)
Last reviewed 19 Apr 2026 · PetCare.AI Editorial Team
Species
Dog, Cat
Brands
5 available
Formulations
2

Mechanism of action

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

At a glance

Class
Intermediate-acting insulin (isophane suspension)
Schedule
Prescription
Storage
MUST be refrigerated (2-8°C). Do NOT freeze. Gently roll before use — do NOT shake. Discard if discoloured or clumped. In-use vials: refrigerate, use within 28 days.

Dosing

🐕

Dog

Diabetes mellitus
Dose
0.25–1 IU/kg
Route
SC
Frequency
BID
Max dose
40 IU/dose; 80 IU/day
Duration: Lifelong; titrate based on blood glucose curves every 1-2 weeks
🐈

Cat

Diabetes mellitus
Dose
0.25–1 IU/kg
Route
SC
Frequency
BID
Max dose
10 IU/dose; 20 IU/day
Duration: Lifelong (unless diabetic remission); start conservative and titrate
Diabetic ketoacidosis (DKA) — transition from regular insulin
Dose
0.25–0.5 IU/kg
Route
SC
Frequency
BID
Max dose
6 IU/dose; 12 IU/day
Duration: Start when eating and stable; transition from CRI regular insulin
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

💉

Injectable suspension — 2

Strength
40 IU/mL (Caninsulin)
Available in India
Strength
100 IU/mL (Humulin N)
Available in India

Storage

MUST be refrigerated (2-8°C). Do NOT freeze. Gently roll before use — do NOT shake. Discard if discoloured or clumped. In-use vials: refrigerate, use within 28 days.

Safety

Absolute contraindications — do not use

  • Hypoglycaemia
    Never administer insulin to a hypoglycaemic patient; correct glucose first

Use with caution

  • Concurrent corticosteroids
    Corticosteroids cause insulin resistance — significantly higher insulin doses required
  • Concurrent progesterone (intact females)
    Diestrus/progesterone causes insulin resistance — spay recommended for diabetic females
  • Inconsistent feeding
    Insulin must be given with meals to prevent hypoglycaemia

Adverse effects

Common
Hypoglycaemia (most common and dangerous)
Weight gain
Injection site reactions
Serious
Severe hypoglycaemia (seizures, coma, death)
Somogyi rebound hyperglycaemia
Insulin-induced hypokalaemia

Monitoring parameters

Blood glucose curves (every 1-2 weeks until stable, then monthly)Fructosamine every 2-4 weeksBody weightWater intake / urine outputClinical signs (PU/PD/PP)Spot blood glucose before insulin dose
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 →

Interactions

No documented interactions.

Brands

International

Caninsulin (Vetsulin)
MSD
Humulin N
Lilly

India

Insulatard
Novo Nordisk
Wosulin N
Wockhardt
Insugen N
Biocon

FAQs

Frequently asked questions

What is Insulin (NPH / Isophane)?
Insulin (NPH / Isophane) is a intermediate-acting insulin (isophane suspension) used in pets. Exogenous insulin that binds to insulin receptors, facilitating glucose uptake into cells, glycogen synthesis, and protein synthesis while inhibiting gluconeogenesis and lipolysis
What is Insulin (NPH / Isophane) used for in pets?
Insulin (NPH / Isophane) is used in veterinary medicine for: Diabetes mellitus; Diabetic ketoacidosis (DKA) — transition from regular insulin.
What is the Insulin (NPH / Isophane) dose for dogs?
For dogs, Insulin (NPH / Isophane) is typically dosed as follows — Diabetes mellitus: 0.25–1 IU/kg SC BID. 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 — Diabetes mellitus: 0.25–1 IU/kg SC BID; Diabetic ketoacidosis (DKA) — transition from regular insulin: 0.25–0.5 IU/kg SC BID. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
What are the side effects of Insulin (NPH / Isophane)?
Common: Hypoglycaemia (most common and dangerous), Weight gain, Injection site reactions. Serious (call your vet immediately): Severe hypoglycaemia (seizures, coma, death), Somogyi rebound hyperglycaemia, Insulin-induced hypokalaemia.
Does Insulin (NPH / Isophane) need a prescription?
Yes. Insulin (NPH / Isophane) is a prescription medication and should only be administered under veterinary supervision.
When should Insulin (NPH / Isophane) not be used?
Do not use Insulin (NPH / Isophane) if: Hypoglycaemia.
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 →

References

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)
Rx
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.
dogcat
Need help? 💬
Chat with us on WhatsApp