Appetite Stimulants in Cats

See your vet immediately if your cat has stopped eating, is vomiting repeatedly, seems weak, or is losing weight. Cats can get very sick after even a short period of poor food intake, and prolonged inappetence raises the risk of hepatic lipidosis, especially in overweight cats. Appetite stimulants can help some cats eat more, but they do not replace finding and treating the reason your cat is not eating.

In cats, the most commonly used appetite stimulants are mirtazapine and capromorelin. Mirtazapine is available as an FDA-approved transdermal ointment called Mirataz for undesired weight loss, and vets may also prescribe oral mirtazapine extra-label. Capromorelin is sold as Elura, an FDA-approved oral solution for management of weight loss in cats with chronic kidney disease. Some vets also use cyproheptadine off-label in selected cases.

These medications are tools, not stand-alone answers. A cat with dental pain, pancreatitis, kidney disease, nausea, constipation, stress, cancer, or another illness may need a broader plan that includes fluids, anti-nausea medication, pain control, diet changes, assisted feeding, or treatment of the underlying disease. Your vet will decide whether an appetite stimulant fits your cat’s situation and which option matches your goals, budget, and cat’s tolerance for medication.

For many pet parents, the biggest practical question is how to get the medicine into a cat that already feels unwell. That is one reason Mirataz is useful. It is applied to the inner ear rather than given by mouth. Elura is an oral liquid and is mainly used in cats with chronic kidney disease. Oral mirtazapine tablets and cyproheptadine can be lower-cost options, but they may be harder to give reliably to a cat that resists pills.

Mirtazapine helps appetite in more than one way. In cats, it is used both as an appetite stimulant and as an anti-nausea medication. That combination matters because many cats do not eat well when they feel queasy. The FDA-approved feline transdermal product, Mirataz, delivers mirtazapine through the skin of the inner ear. Oral mirtazapine is also used extra-label, and Merck notes typical feline dosing intervals differ between the oral and transdermal forms.

Capromorelin works differently. It is a ghrelin receptor agonist, meaning it mimics the body’s hunger-signaling pathway. In cats, Elura is FDA-approved for management of weight loss in cats with chronic kidney disease. In studies reviewed by the FDA, cats receiving Elura gained weight compared with controls. That makes it a targeted option when chronic kidney disease is part of the picture.

Cyproheptadine is another off-label option your vet may consider. It is an antihistamine with serotonin-antagonist effects and has long been used clinically in cats as an appetite stimulant. It is not FDA-approved for this use in cats, but it can be a reasonable option in some cases, especially when a lower-cost oral medication is needed and the cat can be medicated by mouth.

No appetite stimulant fixes every cause of poor appetite. If pain, dehydration, mouth disease, constipation, stress, or severe nausea is the main problem, your vet may pair an appetite stimulant with other treatments or may choose a different first step. In some cats, assisted feeding or a feeding tube is more appropriate than repeatedly changing stimulants.

Side effects depend on the medication used. With mirtazapine, cats may become more vocal, restless, or unusually active. Some cats vomit, and with Mirataz there can also be redness or irritation where the ointment is applied on the ear. Pet parents should wear gloves and follow label directions carefully because the medication is absorbed through skin.

With Elura, the most commonly reported side effects in FDA-reviewed studies were vomiting and hypersalivation. The FDA also notes transient changes in heart rate, blood pressure, and blood glucose in safety testing. Because capromorelin is metabolized in the liver, caution is advised in cats with liver disease. If your cat has diabetes, heart disease, or multiple chronic conditions, your vet may want closer monitoring.

Cyproheptadine and oral mirtazapine can also cause sedation or, in some cats, the opposite effect such as agitation. Any appetite stimulant can make a cat seem hungry without addressing the reason they feel unwell, so worsening vomiting, hiding, drooling, trouble breathing, collapse, or neurologic signs should never be written off as a routine medication reaction.

Call your vet promptly if side effects are mild but persistent, such as repeated vomiting, marked drooling, severe agitation, or refusal to eat despite treatment. Seek urgent care if your cat is weak, collapses, has tremors or seizures, or has not eaten for a day and is getting worse. If you suspect an overdose or accidental exposure, contact your vet or ASPCA Animal Poison Control right away.

Always use appetite stimulants exactly as your vet prescribes. Dosing varies by product, your cat’s weight, kidney and liver function, and whether the medication is being used on-label or extra-label. Merck lists common feline doses of mirtazapine as 2 mg per cat transdermally every 24 hours and 1.88 mg per cat by mouth every 72 hours. For capromorelin, Merck lists 2 mg/kg by mouth every 24 hours in cats.

For Mirataz, the FDA describes applying a 1.5-inch ribbon to the inner, non-hairy part of one ear once daily for 14 days, alternating ears each day. Do not apply it to broken skin, and do not let your cat groom the medication off right after application. Wash your hands or wear gloves as directed. For Elura, the labeled dose is 2 mg/kg, which corresponds to 0.1 mL/kg by mouth once daily, given directly into the mouth with the dosing syringe.

Oral mirtazapine tablets and cyproheptadine are often used extra-label, so the exact schedule may differ from one cat to another. Never substitute a human dose or a dog product on your own. Cats are sensitive to dosing errors, and some medications that are routine in people or dogs can be risky in cats.

If your cat spits out a dose, vomits right after receiving it, or misses a dose, call your vet for instructions rather than doubling the next dose. It is also important to monitor food intake, body weight, hydration, litter box habits, and overall comfort while your cat is on an appetite stimulant. If the medicine is not helping within the timeframe your vet discussed, your cat may need recheck testing or a different plan.

Drug interactions are one of the biggest reasons appetite stimulants should only be used under veterinary guidance. Mirtazapine can interact with other serotonergic medications and monoamine oxidase inhibitors. The FDA summary for Mirataz specifically warns about use with monoamine oxidase inhibitors and serotonergic drugs within 14 days. That matters because cats with chronic illness may already be taking several medications.

Your vet should know about every prescription, over-the-counter product, supplement, probiotic, and compounded medication your cat receives. This includes anti-nausea drugs, pain medications, behavior medications, antihistamines, thyroid medication, blood pressure medication, and anything borrowed from another pet. Even if a combination is sometimes used safely, your vet may want dose adjustments or closer monitoring.

Elura also deserves a full medication review. FDA safety updates note that medication history should include nonprescription products and supplements, and the label was updated with additional user and animal safety warnings in 2025. Because Elura can affect blood glucose and cardiovascular parameters in testing, cats with diabetes, hypertension, heart disease, or liver disease may need a more tailored plan.

If your cat is taking multiple medications and still not eating, ask your vet whether nausea, constipation, pain, or medication side effects could be driving the problem. In many cases, adjusting the overall treatment plan helps more than adding another appetite stimulant.