What safety incidents or poison-control data exist about people using veterinary ivermectin formulations?
Executive summary
Reports from U.S. poison-control centers and clinical toxicology series document a clear rise in human exposures to veterinary ivermectin during the COVID-19 pandemic, with dozens of medically significant cases and multiple hospitalizations tied to ingesting animal formulations and overdosing on human tablets [1] [2]. Regulators including the FDA’s Center for Veterinary Medicine have repeatedly warned that veterinary ivermectin products are not evaluated for human safety and that highly concentrated animal formulations have made people “very sick” [3] [4].
1. What the surveillance numbers show: poison-control spikes and case counts
Poison-control centers reported substantial growth in calls about ivermectin exposures in 2021, with some centers seeing up to five times the pre-pandemic baseline in July 2021, and academic toxicology research identified 37 cases of ivermectin toxicity examined for clinical detail, most requiring emergency or inpatient care [1] [2] [5].
2. Clinical picture: who got sick and how severe were outcomes
The published case series found a median patient age of 64, predominance of men, 21 hospitalizations and 13 emergency-department treatments among 37 cases, neurologic symptoms as the primary toxicity, and at least one death reported in the cohort—indicating that exposures have produced serious, sometimes life‑threatening illness [2] [5].
3. Veterinary formulations stand out for dose, route, and concentration differences
Regulatory and veterinary advisories stress that veterinary products come in highly concentrated “pour‑on,” injectable, paste and drench forms intended for large animals and are not formulated or tested for humans; those formulations can deliver much larger milligram doses than typical human oral tablets and pose unique risks if ingested or administered parenterally [6] [3] [7].
4. Mechanism and manifestations: neurotoxicity at high doses
Authoritative summaries and case reports describe neurologic toxicity—ataxia, impaired consciousness, respiratory depression and vision changes—consistent with known high‑dose effects of ivermectin, with literature noting that high doses and non‑oral routes (not approved for humans) hasten neurotoxic presentations [8] [2] [9].
5. A vivid case: intravenous veterinary ivermectin and rapid neurotoxicity
A peer‑reviewed case report documented a patient who received high-dose oral ivermectin plus an intravenous bolus of a veterinary formulation and developed neurotoxicity; the authors concluded that intravenous administration of veterinary ivermectin was a major factor in the adverse outcome and strongly discouraged parenteral use of any ivermectin formulation in humans [9].
6. Regulatory and professional responses: warnings and outreach
The FDA’s Center for Veterinary Medicine and professional veterinary groups circulated letters and advisories urging retailers and veterinarians to warn customers, stating people have become “seriously ill” after ingesting veterinary ivermectin and emphasizing that animal drugs lack human safety evaluations [3] [7] [4].
7. Limitations and remaining unknowns in the data
Available reporting documents case series, poison‑center trends, regulatory letters and case reports but does not provide a comprehensive numerator/denominator calculation of all exposures, nor exhaustive pharmacovigilance linking every adverse event to a specific formulation or dose; thus the true incidence of serious harm from veterinary ivermectin in the population cannot be precisely derived from the cited sources [1] [2] [3].
8. Bottom line: avoid veterinary products and seek medical guidance
The collected evidence shows repeated, documented harms when people ingest or receive veterinary ivermectin—particularly high‑concentration or parenteral products—producing hospitalizations and neurotoxicity and prompting formal regulatory warnings; human‑use ivermectin is a distinct, regulated product and veterinary formulations should not be used in humans [2] [3] [6].