Drug profile

The FDA adverse-event record for Zeranol Implant

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

102
adverse-event reports
33.3%
death-coded share
Cattle
most-reported species
30
Death - top reaction
Verify with FDA CVM →
Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
102
Total Reports
34
Deaths Reported
33.3%
Death Rate

Active Ingredients

Zeranol Implant

Administration Routes

UnknownSubcutaneousParenteralOther

Species Affected

Cattle 52
Unknown 44
Human 6

Most Affected Breeds

Unknown 50
Cattle (other) 22
Aberdeen Angus 11
Crossbred Bovine/Cattle 10
Red Angus 4
Holstein-Friesian also known as Holstein 2
Cattle (unknown) 1
Charolais 1
Cattle (unspecified) 1

Most Reported Reactions

Death 30
Lack of efficacy - NOS 18
Product problem 17
Uncoded sign 16
Device Defective NOS 15
Product Defect, General 12
Dispenser, Abnormal 9
Lack of efficacy (bacteria) - NOS 7
Containers, Damaged 6
Difficulty of Use 6
Implant, Abnormal 5
Lateral recumbency 4

Outcome Breakdown

Died
33 (37.9%)
Ongoing
20 (23.0%)
Outcome Unknown
17 (19.5%)
Recovered/Normal
13 (14.9%)
Euthanized
3 (3.4%)
Recovered with Sequela
1 (1.1%)

Zeranol Implant Adverse Event Insights

102 reports name Zeranol Implant; 34 recorded a death outcome (33.3% of reported events, not a population-level mortality rate). Active ingredient: Zeranol Implant. Administration routes: Unknown, Subcutaneous, Parenteral, Other.

By species: Cattle (52 reports), Unknown (44 reports), Human (6 reports). By breed: Unknown (50), Cattle (other) (22), Aberdeen Angus (11).

Leading clinical signs: Death (30), Lack of efficacy - NOS (18), Product problem (17), Uncoded sign (16). Outcome, 87 coded reports: Died leads at 37.9%.

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.