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Mirtazapine: Generic & Mirataz® (Appetite Stimulant)
Mirtazapine is a prescription appetite stimulant used in cats and dogs, available here as generic 15 mg and 30 mg tablets and as Mirataz, the FDA-approved mirtazapine transdermal ointment for the management of weight loss in cats. Mirtazapine increases appetite and helps reduce nausea, often stimulating eating within hours of a dose, which makes it a mainstay for cats with chronic kidney disease and other pets whose poor appetite threatens recovery.
Key facts
- Active ingredient: mirtazapine — 15 mg or 30 mg tablets, or Mirataz transdermal ointment
- Species: cats and dogs (Mirataz is FDA-approved for cats)
- Available sizes: 15 mg and 30 mg tablets in 30-count bottles; Mirataz 5 g tube
- Form: oral tablet, or transdermal ointment applied to the inner ear
- Typical uses: appetite stimulation and weight-loss management, support during chronic kidney disease, recovery from illness or surgery, nausea reduction
- Prescription status: requires authorization from your veterinarian
How to use
For Mirataz, apply a 1.5-inch ribbon of ointment to the inner surface of your cat's ear pinna once daily for 14 days, alternating ears, while wearing disposable gloves; wash your hands afterward. For tablets, your prescribing veterinarian determines the dose and frequency — cats typically need only a fraction of a tablet, while dogs are dosed by body weight. Give exactly as directed by your veterinarian.
Safety information
The most common side effects are hyperactivity, vocalization, and increased affection or agitation; Mirataz can also cause temporary redness at the application site. Avoid combining mirtazapine with other serotonergic drugs (fluoxetine, trazodone, tramadol, selegiline) without veterinary guidance because of the rare risk of serotonin syndrome. Dose reductions may be needed in pets with kidney or liver disease. Wear gloves when applying the transdermal ointment and avoid touching treated ears until the site is dry.
Frequently asked questions
How does mirtazapine stimulate appetite?
Mirtazapine acts on serotonin and adrenergic receptors in the brain, which increases appetite and reduces nausea — helping pets feel hungry rather than queasy.
How fast does mirtazapine work?
Many pets show increased interest in food within hours of a dose; in the Mirataz field study, treated cats gained measurable body weight within 14 days.
What is Mirataz and how is it applied?
Mirataz is an FDA-approved mirtazapine transdermal ointment for weight loss in cats. A 1.5-inch ribbon is applied to the inner ear once daily for 14 days — no pilling required.
Can dogs take mirtazapine?
Yes — veterinarians commonly prescribe mirtazapine tablets off-label for dogs with poor appetite or nausea; the dose is set by your veterinarian based on body weight.
Is a prescription required for mirtazapine?
Yes. Mirtazapine and Mirataz are prescription medications that must be authorized by your veterinarian based on a current veterinarian-client-patient relationship.
Learn more in our guide, What You Need to Know About Mirtazapine.