Drug profile

The FDA adverse-event record for Cyproheptadine

41 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Cyproheptadine. See the species affected, top reactions, and outcomes below.

41
adverse-event reports
22.0%
death-coded share
Cat
most-reported species
11
Weight loss - top reaction
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Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
41
Total Reports
9
Deaths Reported
22.0%
Death Rate

Active Ingredients

Cyproheptadine

Administration Routes

OralUnknownRectal

Species Affected

Cat 32
Dog 7
Horse 1
Human 1

Most Affected Breeds

Domestic Shorthair 14
Cat (unknown) 4
Domestic Longhair 4
Siamese 2
Cat (other) 2
Tonkinese 2
European 1
Crossbred Canine/dog 1
Thoroughbred 1
Shepherd Dog - German 1

Most Reported Reactions

Weight loss 11
Ataxia 6
Vomiting 6
Anorexia 6
Lack of efficacy - NOS 6
Death 5
Behavioural disorder NOS 5
Diarrhoea 5
Decreased appetite 5
Death by euthanasia 4
Lethargy (see also Central nervous system depression in 'Neurological') 4
Nausea 4

Outcome Breakdown

Outcome Unknown
13 (31.7%)
Ongoing
10 (24.4%)
Recovered/Normal
7 (17.1%)
Died
5 (12.2%)
Euthanized
4 (9.8%)
Recovered with Sequela
2 (4.9%)

Cyproheptadine Adverse Event Insights

41 reports name Cyproheptadine; 9 recorded a death outcome (22.0% of reported events, not a population-level mortality rate). Active ingredient: Cyproheptadine. Administration routes: Oral, Unknown, Rectal.

By species: Cat (32 reports), Dog (7 reports), Horse (1 reports). By breed: Domestic Shorthair (14), Cat (unknown) (4), Domestic Longhair (4).

Leading clinical signs: Weight loss (11), Ataxia (6), Vomiting (6), Anorexia (6). Outcome, 41 coded reports: Outcome Unknown leads at 31.7%.

Read these counts as reporting volume, not risk: per our methodology, a widely-prescribed drug will rack up more raw FDA reports in a given year than a rarely-used one at an identical true rate, so we recommend comparing within similar-exposure products rather than across the full 2025 catalog.

Source: FDA Center for Veterinary Medicine openFDA Animal & Veterinary Adverse Events (CVM AER) · 2025

Every figure on PlainBreed is rendered directly from FDA openFDA adverse event data, no number is typed in by an editor. This page draws directly on FDA openFDA data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.