Skip to main content
PetDosageChart

Appetite stimulant / Tetracyclic antidepressant · For Cats

How much Mirataz (Mirtazapine) can I give my cat?

Standard Mirataz dose for cats is 0.5 mg per kg (0.23 mg per lb), given every 48-72 hours (oral) or daily (transdermal Mirataz). Use the calculator below for your cat's exact weight, or jump to the weight-by-weight chart.

Onset
1-2 hours
Duration
48-72 hours in cats
Class
Appetite stimulant / Tetracyclic antidepressant

Calculator estimate from Plumb’s Veterinary Drug Handbook. Not yet vet-reviewed — see our methodology .

This dosage information is for educational purposes only. Always consult your veterinarian before giving any medication to your pet. Dosages may vary based on your pet's health conditions, other medications, and individual factors.

Content reviewed by licensed veterinarians. Sourced from Plumb's Veterinary Drug Handbook and the Merck Veterinary Manual.

Dosage Calculator · 01

Enter your cat's weight

By Weight

Mirataz dose by cat weight

Pick your cat's weight to jump to a dedicated page with the dose, frequency, safety notes, and FAQ for that size.

Embed this calculator on your site

Get a free Mirataz dosage widget

Get embed code

Free forever. Works in any blog post or article. Adds a small "Powered by petdosagechart.com" credit at the bottom.

Dosage Chart · 02

Mirataz dosage for cats by weight

Scroll sideways to see full table

Weight Low Dose Standard Max Safe Frequency
3 lbs (1.4 kg) 0.5mg 0.5mg 1mg every 48-72 hours (oral) or daily (transdermal Mirataz)
4 lbs (1.8 kg) 0.5mg 1mg 1.5mg every 48-72 hours (oral) or daily (transdermal Mirataz)
5 lbs (2.3 kg) 1mg 1mg 1.5mg every 48-72 hours (oral) or daily (transdermal Mirataz)
6 lbs (2.7 kg) 1mg 1.5mg 2mg every 48-72 hours (oral) or daily (transdermal Mirataz)
7 lbs (3.2 kg) 1.5mg 1.5mg 2.5mg every 48-72 hours (oral) or daily (transdermal Mirataz)
8 lbs (3.6 kg) 1.5mg 2mg 2.5mg every 48-72 hours (oral) or daily (transdermal Mirataz)
9 lbs (4.1 kg) 1.5mg 2mg 3mg every 48-72 hours (oral) or daily (transdermal Mirataz)
10 lbs (4.5 kg) 2mg 2.5mg 3.5mg every 48-72 hours (oral) or daily (transdermal Mirataz)
12 lbs (5.4 kg) 2mg 2.5mg 4mg every 48-72 hours (oral) or daily (transdermal Mirataz)
14 lbs (6.3 kg) 2.5mg 3mg 4.5mg every 48-72 hours (oral) or daily (transdermal Mirataz)
16 lbs (7.3 kg) 3mg 3.5mg 5.5mg every 48-72 hours (oral) or daily (transdermal Mirataz)
18 lbs (8.2 kg) 3.5mg 4mg 6mg every 48-72 hours (oral) or daily (transdermal Mirataz)
20 lbs (9.1 kg) 3.5mg 4.5mg 7mg every 48-72 hours (oral) or daily (transdermal Mirataz)
25 lbs (11.3 kg) 4.5mg 5.5mg 8.5mg every 48-72 hours (oral) or daily (transdermal Mirataz)

Common Uses · 03

What is Mirataz (Mirtazapine) used for in cats?

appetite stimulation weight loss in chronic kidney disease nausea reduction appetite loss from cancer or chemotherapy

Administration · 04

How to give Mirataz to your cat

Cats metabolize mirtazapine much more slowly than dogs or humans, so dosing must be every 48-72 hours for oral tablets — never daily. A typical oral dose is 1/8 to 1/4 of a 15 mg tablet (1.88-3.75 mg). The FDA-approved transdermal ointment (Mirataz) is applied to the inner ear flap daily with a gloved finger — rotate ears and wipe the old dose off before applying a new one. For oral tablets, you can hide them in a pill pocket or give directly using a pill gun.

Available Forms

tablet, transdermal ointment

Give with Food?

No — can be given without food

Side Effects · 05

Side effects of Mirataz in cats

Common side effects

vocalization
restlessness
increased affection or kneading
mild sedation

Serious side effects — call your vet

  • serotonin syndrome (tremors, agitation, high heart rate)
  • severe sedation
  • liver toxicity with overdose
  • abnormal heart rhythms

Emergency · 06

When to call the vet

Call your vet immediately if your cat shows any of these signs:

  • Tremors, twitching, or agitation (signs of serotonin syndrome)
  • Extreme sedation or inability to stand
  • Rapid or irregular heartbeat
  • Vomiting that does not stop after 24 hours
  • Yellowing of gums or skin (jaundice)

Related · 08

Related medications for cats

Sources · 09

Sources & references

The dosage information on this page is compiled from the following veterinary and pharmaceutical references:

  • Plumb's Veterinary Drug Handbook — the standard veterinary pharmacology reference used by veterinarians worldwide.
  • Merck Veterinary Manual — a trusted, peer-reviewed resource for veterinary professionals and pet owners.
  • DailyMed (FDA Drug Labels) — official FDA-approved drug labeling and prescribing information for Mirtazapine.

Read more about our methodology and how we calculate dosages.

Transparency · 11

How this page was made

Sourced from Plumb's Veterinary Drug Handbook, the reference used in US vet schools. Every dose, frequency, and tablet count on this page is generated from that data, then checked against the published references below.

Sources cited
  • Plumb's Veterinary Drug Handbook
  • Merck Veterinary Manual
Calculator formula
Doses scale linearly from a standard basis of 0.5 mg per kg (0.23 mg per lb) of body weight, given every 48-72 hours (oral) or daily (transdermal Mirataz). The calculator multiplies that basis by your cat's weight and rounds to the closest available tablet size.
Last-reviewed status
Automated from Plumb’s, not yet vet-reviewed.

More on our methodology and editorial process — how we source, calculate, and review cats dosage data.

Frequently Asked · 07

Questions about this medication

Why can cats only get mirtazapine every other day?
Cats metabolize mirtazapine significantly slower than humans or dogs. The half-life in cats is approximately 15-20 hours, compared to about 2-4 hours in dogs. Giving it daily orally can lead to drug accumulation and toxicity, including serotonin syndrome. The transdermal formulation (Mirataz) is specifically dosed for daily application in cats.
How quickly does mirtazapine make a cat want to eat?
Most cats show increased interest in food within 1-2 hours of administration. The appetite-stimulating effect typically peaks within a few hours and can last 48-72 hours. Offer your cat their favorite food shortly after giving the medication for best results.
Is mirtazapine safe for cats with kidney disease?
Yes, mirtazapine is commonly and safely used in cats with chronic kidney disease (CKD) to combat appetite loss and weight loss. However, because CKD can slow drug metabolism further, your vet may recommend a lower dose or longer interval between doses. The transdermal form (Mirataz) is FDA-approved specifically for weight loss in cats.
Can I use human mirtazapine for my cat?
Human mirtazapine tablets (typically 15 mg) can be used but must be carefully dosed — cats need only 1/8 to 1/4 of a tablet. The FDA-approved transdermal ointment Mirataz is specifically formulated for cats and is easier to dose accurately. Never give a whole human tablet to a cat.
What are signs of mirtazapine overdose in cats?
Signs of overdose include agitation, vocalization, tremors, rapid heart rate, disorientation, and seizures — collectively known as serotonin syndrome. If you suspect an overdose, contact your veterinarian or an animal poison control hotline immediately. Due to the long half-life in cats, symptoms can persist for 24+ hours.

Safety · 10

More resources