What are the health risks of taking horse paste ivermectin for humans?
Executive summary
Medical authorities warn that veterinary ivermectin (horse paste) is not approved for human use and can cause serious toxicity — including nausea, vomiting, low blood pressure, allergic reactions, dizziness, loss of coordination, seizures, coma and death (FDA). Manufacturers and sellers state the paste "has not been tested in humans" and explicitly say "NOT INTENDED FOR HUMAN CONSUMPTION" (Farnam; horse.com) [1] [2] [3].
1. Why people used horse paste: low cost, easy access, and online hype
During periods of heightened interest in ivermectin, people sought alternatives to prescription human tablets because veterinary paste is inexpensive, widely sold online, and promoted in forums and videos — a dynamic described in reporting where buyers admitted preferring horse paste to uncertain foreign-sourced pills and followed DIY dosing guides found on YouTube (Blaze Media) [4]. Available sources do not provide systematic data on how many people used horse paste, but anecdotal accounts and media reporting document the pattern [4].
2. What the labels and manufacturers say: not for humans, not tested in people
Every product page and manufacturer material in the sources makes the same point: equine ivermectin pastes are labeled for horses only, not for human consumption, and "has not been tested in humans" or "not approved for use with humans" (horse.com product page; Farnam IverCare label; Drugs.com vet monograph) [3] [2] [5]. Retailers also warn about environmental harm (to fish) and dosing by animal weight, underscoring that formulations and concentrations are designed for large animals [6].
3. Documented health risks reported by authorities
The U.S. Food and Drug Administration (FDA) lists a range of serious adverse effects from ivermectin overdose or inappropriate use in humans: nausea, vomiting, diarrhea, hypotension (low blood pressure), allergic reactions (itching, hives), dizziness, ataxia (loss of balance), seizures, coma and death [1]. The FDA also states it has not authorized ivermectin for prevention or treatment of COVID-19 and that available clinical trials do not show effectiveness for that use [1].
4. Why veterinary paste is riskier than prescription human ivermectin
Veterinary pastes are formulated, dosed, and concentrated for animals that weigh hundreds to thousands of pounds; syringes mark doses for 250–1,250 lb horses, not people. Manufacturers caution about precise weight-based dosing for horses and note the product contains enough paste for a 1,250 lb horse at 91 mcg per pound, demonstrating how different intended concentrations and delivery systems are from human tablets (Farnam product information; product listings) [2] [6]. Such mismatches increase the risk of accidental overdose or exposure to inappropriate excipients; available sources do not detail human pharmacokinetics for the paste specifically.
5. Reported severe outcomes and the broader public-health angle
Reporting and industry guides recount severe events linked to misuse of animal ivermectin, and warn that misuse can delay effective care. One source characterizes the pandemic-era surge in veterinary-ivermectin self-treatment as part of misinformation flows and notes tragic cases where individuals who self-treated suffered fatal outcomes (toltrazurilshop summary; Blaze Media narrative) [7] [4]. The FDA frames the problem both as direct harm from toxicity and as a public-health risk when people forego proven therapies [1].
6. Conflicting viewpoints and information gaps
Some online guides and communities circulated informal dosing advice for humans using horse paste; one site even published a "dosage guide" addressed to lay readers (ivermectin.cat) [8]. These grassroots sources promoted safe-sounding protocols despite manufacturer and regulator warnings. Available sources do not include controlled clinical evidence supporting the safety or efficacy of veterinary paste in humans, nor do they quantify frequency of serious adverse events from paste specifically; regulators rely on pharmacovigilance and case reports rather than randomized trials for this problem [1] [2].
7. Bottom line and practical guidance
Regulatory and manufacturer materials converge: veterinary ivermectin paste is not for humans, has not been tested in people, and can cause life-threatening toxicity if misused [3] [2] [1]. If someone has taken veterinary ivermectin and feels unwell — symptoms like gastrointestinal distress, dizziness, seizures, or trouble breathing — the FDA guidance in the reporting recommends seeking immediate medical attention [1]. Available sources do not list specific hospital treatment protocols for paste exposure; clinicians manage toxicity based on symptoms and standard supportive care [1].
Limitations: this article uses only the supplied sources. Available sources do not provide population-level incidence of adverse events specifically from horse-paste misuse nor detailed clinical treatment algorithms for such exposures; they report manufacturer labeling, regulator warnings, anecdotal media accounts and harm summaries [3] [2] [1] [4] [7] [8].