What are the recommended dosages for ivermectin preventative care?
Executive summary
There is no accepted, evidence-based "preventative care" dosage of oral ivermectin for COVID-19 endorsed by major health authorities; ivermectin is approved and dosed for specific parasitic diseases, typically as a single weight‑based dose of about 200 micrograms per kilogram (mcg/kg) for adults and children ≥15 kg (Mayo Clinic, Drugs.com) [1] [2]. Regulatory agencies warn against using veterinary formulations or unsupervised ivermectin for COVID prevention because trials and systematic reviews have not established benefit and overdoses can cause serious harm (FDA, Drugs.com, systematic review) [3] [4] [5].
1. What "recommended dosages" exist in official prescribing guidance for approved uses
For approved human uses—onchocerciasis, strongyloidiasis and some ectoparasitic infestations—oral ivermectin dosing is weight‑based and usually given as a single dose of about 200 mcg/kg; exact dosing must be determined by a clinician and tablet strengths vary (Mayo Clinic; Medical News Today; Drugs.com) [1] [6] [2]. Some conditions require repeat or multi‑day regimens—crusted scabies, for example, may need two or more doses spaced one to two weeks apart, and some dermatology guidance notes repeat dosing when single doses fail to kill newly hatched mites (Drugs.com; Next Steps in Dermatology) [2] [7]. Topical ivermectin (1% lotion/cream) is a separate formulation with its own labeling for conditions such as rosacea and head lice (Mayo Clinic topical page) [8].
2. Why there is no validated "preventive care" dose for COVID-19
Multiple high‑quality authorities and evidence syntheses conclude there is insufficient proof that ivermectin prevents COVID-19 or reduces meaningful clinical outcomes; the U.S. Food and Drug Administration has not authorized ivermectin for prevention or treatment of COVID‑19 and cautions against self‑medication, and systematic reviews of randomized trials have found no reliable mortality or hospitalization benefit in outpatients (FDA; systematic review; NEJM trial discussion) [3] [5] [9]. Individual small trials and pilot studies have explored varied regimens—single doses, five‑day courses, or combinations with doxycycline—but results are heterogeneous, often at high risk of bias, and have not produced a consensus prophylactic regimen accepted by public health agencies (PMC pilot study; NEJM; systematic review) [10] [9] [5].
3. Harm, dosing mistakes, and the veterinary‑product problem
Public health warnings highlight that people have taken veterinary formulations and overdosed on ivermectin intended for animals; animal products differ in concentration and excipients and can cause nausea, hypotension, neurologic events, seizures, coma or death when misused in humans (FDA; Drugs.com) [3] [4]. Even human formulations have dose limits: labeled dosing, precautions for hepatic disease, and pediatric weight cutoffs (not generally recommended under 15 kg) are standard because safety and pharmacokinetics change with dose, age, and comorbidities (Mayo Clinic; Next Steps in Dermatology; Drugs.com) [1] [7] [2].
4. Who recommends prophylactic ivermectin and why their guidance differs from regulators
Some advocacy groups and clinician networks have promoted prophylactic or early‑treatment ivermectin protocols and published community guidance—examples include the Canadian Covid Care Alliance and FLCCC proponents—but their protocols are not aligned with FDA/WHO/CDC guidance and often rely on observational data, selective trials, or reinterpretations of in vitro antiviral signals; these groups frequently frame ivermectin as a low‑cost, broadly available option and may have implicit agendas that challenge mainstream vaccine and treatment narratives (Canadian Covid Care Alliance; FLCCC referenced) [11]. Regulatory positions emphasize randomized trial evidence, safety surveillance, and population‑level benefit, which those advocacy protocols have not demonstrated to the satisfaction of major public health bodies [3] [5].
5. Practical bottom line for clinicians and the public
For approved parasitic uses, follow clinician‑prescribed, weight‑based dosing—commonly ~200 mcg/kg as a single dose and specific repeat intervals when indicated—and do not repurpose those regimens as "preventive care" for COVID‑19 because no authoritative body has validated such a use; consult clinicians for approved vaccines, proven therapies, and for safe prescribing if parasitic infection is suspected (Mayo Clinic; Drugs.com; FDA) [1] [2] [3]. If there is interest in ivermectin for COVID‑19 prevention or early treatment, the evidence and regulatory stance require that this be explored only in properly designed clinical trials rather than by unsupervised self‑dosing (NEJM; systematic review) [9] [5].