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Metformin

Prescription

Biguanide Antidiabetic Agent

Last reviewed 21 Apr 2026 · PetCare.AI Editorial Team

Species

Dog, Cat

Brands

1 available

Interactions

2 documented

Formulations

Mechanism of action

Reduces hepatic glucose production (gluconeogenesis), enhances peripheral insulin sensitivity, and reduces intestinal glucose absorption. Does not stimulate insulin secretion — no hypoglycemia risk when used alone. Also has anti-inflammatory and anti-neoplastic properties.

At a glance

Class

Biguanide Antidiabetic Agent

Schedule

Prescription

Storage

Store at room temperature below 30°C, protect from light and moisture

Dosing

🐕

Dog

Off-label for insulin-resistant diabetes (adjunct to insulin)

Dose

25–50 mg/dog

Route

Frequency

q12h

🐈

Cat

Investigational for feline Type 2 diabetes as adjunct to insulin or glipizide

Dose

25–50 mg/cat

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 — 3

Strength

—

Strength

—

Strength

—

Storage

Store at room temperature below 30°C, protect from light and moisture

Safety

Monitoring parameters

Blood glucose curvesRenal function (creatinine)Lactate (if clinical suspicion)GI toleranceB12 levels with chronic use

Educational reference only

Interactions

Major — 1

Prednisolone

major

Corticosteroids directly antagonize metformin's insulin-sensitizing effect by increasing hepatic gluconeogenesis and peripheral insulin resistance.

Management: Avoid steroids with metformin. If unavoidable, metformin alone will be inadequate — insulin therapy likely needed.

Moderate — 1

Furosemide

moderate

Furosemide may reduce metformin renal clearance, increasing metformin levels and lactic acidosis risk. Furosemide-induced dehydration further increases risk.

Management: Monitor renal function and hydration. Lactic acidosis risk increases with dehydration or renal impairment.

Educational reference only

Brands

Other markets

Glucophage

FAQs

Frequently asked questions

›What is Metformin?

Metformin is a biguanide antidiabetic agent used in pets. Reduces hepatic glucose production (gluconeogenesis), enhances peripheral insulin sensitivity, and reduces intestinal glucose absorption. Does not stimulate insulin secretion — no hypoglycemia risk when used alone. Also has anti-inflammatory and anti-neoplastic properties.

›What is Metformin used for in pets?

Metformin is used in veterinary medicine for: Off-label for insulin-resistant diabetes (adjunct to insulin); Investigational for feline Type 2 diabetes as adjunct to insulin or glipizide.

›What is the Metformin dose for dogs?

For dogs, Metformin is typically dosed as follows — Off-label for insulin-resistant diabetes (adjunct to insulin): 25–50 mg/dog PO q12h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.

›What is the Metformin dose for cats?

For cats, Metformin is typically dosed as follows — Investigational for feline Type 2 diabetes as adjunct to insulin or glipizide: 25–50 mg/cat PO q12h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.

›Does Metformin need a prescription?

Yes. Metformin 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