What are the FDA‑approved human uses and dosing guidelines for ivermectin?
Executive summary
Ivermectin is FDA‑approved for a small set of parasitic indications in humans—oral tablets for certain internal worms and topical formulations for external parasites and some skin conditions—but it is not authorized or approved by the FDA to prevent or treat COVID‑19 or other viral infections [1] [2] [3]. Approved human dosing is weight‑based and varies by condition and formulation; veterinary preparations are different products and must never be substituted for human formulations [1] [4].
1. What the FDA has approved: narrow, specific uses
The U.S. Food and Drug Administration’s public guidance states that ivermectin tablets are approved in humans for treatment of certain parasitic worms, and there are topical (skin) formulations approved for head lice and skin conditions such as rosacea, with these approvals representing the drug’s legitimate, regulated human uses [1] [4].
2. How approved dosing is described: weight‑based, indication‑dependent
Approved human dosing is calculated by body weight and differs by indication: authoritative summaries and medical resources cite typical regimens in the range of about 150–200 micrograms per kilogram (mcg/kg) of body weight for many parasitic indications, administered as a single oral dose or at intervals determined by the target disease (for example, once or twice yearly for some mass‑treatment programs), though exact schedules depend on the specific FDA‑approved indication and product labeling [5] [6] [1].
3. Dosing examples and off‑label protocols in circulation
Clinical and academic discussions note that some protocols and non‑FDA treatment guides have proposed higher or repeated dosing—numbers such as 0.4–0.6 mg/kg per day have appeared in various unofficial protocols—but these represent off‑label or investigational regimens and are not FDA approvals; the scientific literature and public‑health agencies have warned that the concentrations needed to inhibit SARS‑CoV‑2 in vitro are far higher than standard human doses and therefore such higher dosing raises safety concerns [6] [2].
4. The COVID‑19 controversy: not FDA‑approved and safety signals
Multiple authoritative reviews and the FDA itself emphasize that ivermectin has not been authorized or approved for prevention or treatment of COVID‑19 and that the NIH and WHO have concluded there is insufficient evidence to recommend it for COVID‑19 outside clinical trials; increased human exposures and poison control reports during the pandemic prompted regulatory warnings against using veterinary formulations or escalating doses [2] [3] [1].
5. Safety, interactions, and the veterinary product hazard
The FDA explicitly warns that animal ivermectin products are different formulations not tested for human safety and that taking large or inappropriate doses can cause serious harm; even approved human doses can interact with other drugs (for example, blood thinners) and higher‑than‑recommended doses can produce nausea, dizziness, neurologic effects and other toxicities documented in poison‑control reports [1] [2] [4].
6. How to interpret conflicting sources and next steps
Scientific reviews, clinical trials, and public‑health agencies present alternative viewpoints—some small trials or in‑vitro studies suggested antiviral activity but required concentrations far above approved dosing—so the consistent regulatory position from FDA, NIH and WHO is precautionary: use FDA‑approved indications and doses, avoid veterinary products, and restrict experimental or higher‑dose uses to controlled clinical trials where safety and efficacy can be properly evaluated [2] [3] [1].