How do ivermectin concentrations differ between veterinary injectable/gel and human oral tablets (mg per kg)?
Executive summary
Human oral ivermectin tablets are dosed at about 0.15–0.20 mg per kg for approved single-dose parasitic treatments, while veterinary products—especially large‑animal formulations—contain far higher concentrations per unit and are sold in formats (pastes, injectables, pour‑ons) intended to deliver much larger mg/kg doses to horses, cattle or sheep; using those products in people has caused reported overdoses and poisonings [1] [2] [3]. Public health authorities warn that veterinary ivermectin is “much higher dosage” than human tablets and is not approved for treating COVID‑19 [4] [2].
1. Human approved dosing: small mg/kg tablets used for specific parasitic infections
Approved human ivermectin dosing is low by weight — standard single doses for many indications are about 0.15–0.20 mg/kg (the FDA‑approved single‑dose range cited on clinical and review pages and summarized in dosing guides) — and human products are manufactured as oral tablets with tight regulatory controls on concentration per tablet and intended mg/kg use (available sources describe human tablets and dosing ranges and list the approved indications) [5] [6] [2] [1].
2. Veterinary formulations: higher concentration and different delivery intended for large animals
Veterinary ivermectin comes in pastes, injectables, pour‑ons and high‑concentration gels formulated to deliver large mg/kg doses for horses, cattle and other livestock; those products are produced to treat much heavier animals and therefore the container concentrations and per‑dose mg amounts are far larger than a human oral tablet (sources note pour‑on, injectable, paste, chewable and drench formats and emphasize higher per‑unit concentrations) [2] [7].
3. Concrete contrast: why milligrams per kilogram differ in practice
In practice the difference is not a single standard number because veterinary products are sold as high‑strength pastes or injectables calibrated for animal weights rather than as 3–12 mg human tablets. Commentaries and medical outlets repeatedly state that animal formulations are “much higher dosage” and can produce toxic mg/kg exposure if used by humans — the Cleveland Clinic specifically notes animal ivermectin is at much higher dosage than what a doctor would prescribe for a person [4] [2] [3].
4. Toxicity context: human LD50, in‑vitro antiviral concentrations, and safety margins
Toxicology summaries show the approved human single dose (≈0.15–0.20 mg/kg) is far below the ranges linked to serious toxicity: mouse and dog LD50 data and converted human‑equivalent estimates imply much higher doses (Wikipedia summary reports an approximated human‑equivalent LD50 range and contrasts it with the 0.150–0.200 mg/kg approved usage). In vitro antiviral activity against SARS‑CoV‑2 required concentrations corresponding to oral doses far above the approved human dose (an estimate of ~7.0 mg/kg, roughly 35× the maximum FDA‑approved dose, is cited), illustrating the narrow margin between hypothesized antiviral effect and toxic exposures [1].
5. Real‑world harms and price/availability consequences
Reports and reviews document people taking veterinary ivermectin intended for animals (including horses) and suffering adverse effects; veterinary formulations became sought and sometimes price‑gouged during the COVID‑19 misinformation surge. Academic price comparisons documented a spike in demand and veterinary product price rises, and veterinary literature records overdoses in non‑target species after administration of equine products [8] [3].
6. What the authorities and major clinical sources say — competing perspectives
Regulatory and clinical sources uniformly state ivermectin is not authorized for COVID‑19 and warn against using animal products in people; this is the consensus view in the provided sources [2] [5]. Some laboratory studies and reviews note ivermectin has in‑vitro antiviral activity, but sources emphasize that the concentrations producing that effect exceed safe human dosing [1] [9]. Available sources do not present a vetted, authoritative conversion table listing exact mg/kg contents for each veterinary product versus human tablets.
7. Practical takeaway for clinicians and the public
Do not substitute veterinary ivermectin for human tablets: the formulations differ in concentration, intended mg/kg delivery and excipients, and using animal products risks overdose and poisoning. For precise mg/kg dosing in a human patient, use approved human ivermectin tablets and follow medical guidance; for veterinary dosing, follow veterinary product labels and veterinarian direction [2] [4] [3].
Limitations: the supplied sources describe dosing ranges, product forms and toxicity context but do not provide a single comprehensive table comparing mg/kg concentrations for every veterinary injectable/gel vs each human tablet strength; therefore readers seeking exact mg/ml or mg/g comparisons for a specific veterinary brand must consult that product’s label or a veterinarian (available sources do not mention a universal conversion chart) [7] [1].