What are approved human medical indications and standard dosages for ivermectin (e.g., parasitic infections like strongyloidiasis, onchocerciasis)?
Executive summary
Ivermectin is an antiparasitic medication approved for specific human uses including oral treatment of intestinal strongyloidiasis and onchocerciasis, and topical formulations for certain dermatologic conditions such as rosacea and lice; major health agencies explicitly advise that it is not authorized for COVID-19 [1] [2] [3]. Standard systemic dosing is weight-based, most commonly a single oral dose around 150–200 micrograms per kilogram for many indications, with repeat intervals and regimens varying by disease and programmatic use [4] [5] [6].
1. Approved human medical indications — what regulators list
Regulatory and reference sources concur that oral ivermectin is approved as a broad-spectrum antiparasitic for intestinal strongyloidiasis (Strongyloides stercoralis) and onchocerciasis (Onchocerca volvulus), and that topical ivermectin preparations are approved for rosacea and for lice/scabies in some jurisdictions; major U.S. agencies emphasize these are the established human uses [1] [2] [6].
2. Standard oral dosages — weight‑based single doses and programmatic repeats
For systemic (oral) therapy, dosing is weight‑based: commonly 150 micrograms/kg as a single dose for many programs, with some references and labeling indicating 200 micrograms/kg for certain regimens; tablets are typically 3 mg each and clinicians calculate doses by body weight, and treatments may be repeated at intervals ranging from months to yearly depending on the infection and public‑health program [4] [5] [7].
3. Disease‑specific dosing and frequency — onchocerciasis and strongyloidiasis
Onchocerciasis is often managed in mass‑drug administration programs with a single oral dose of ivermectin (commonly 150–200 mcg/kg) repeated on a public‑health schedule (for example, every 3–12 months in some contexts), while strongyloidiasis is treated with single-dose weight‑based ivermectin and may require repeat dosing based on clinical response and local guidance; exact intervals and regimens depend on the condition and clinical judgment [4] [6] [8].
4. Other uses cited in literature — dermatology and neglected tropical diseases
Beyond the two core FDA‑approved systemic indications, ivermectin is used internationally to treat additional parasitic infections (including some soil‑transmitted helminths, lymphatic filariasis, cutaneous larva migrans, and ectoparasites), and topical ivermectin has recognized dermatologic roles such as rosacea and lice treatment, with WHO and other bodies using ivermectin widely in neglected tropical disease control [6] [9] [10].
5. Safety, interactions and formulation cautions
Ivermectin has a long safety record in humans but can interact with drugs that affect P‑glycoprotein transport and has neurologic and other adverse‑event reports that warrant monitoring; animal formulations differ in concentration and excipients, and health authorities warn against using veterinary products in people because of toxicity reports and hospitalizations [8] [5] [3].
6. What ivermectin is not approved for — COVID‑19 and overextension of evidence
Regulators including the U.S. FDA and public information sources state that ivermectin has not been authorized or approved to prevent or treat COVID‑19 in humans, and laboratory in vitro antiviral activity would require doses far above approved human limits—levels associated with toxicity—so major agencies advise against such use [3] [10] [2].
7. Gaps, evolving approvals, and international variations
While core approved indications are consistent, international practice and recent regulatory opinions (for example on fixed‑dose combinations or expanded parasitic indications) can evolve, and some agencies or programs use ivermectin in broader public‑health campaigns; specifics of dosing and approved age/weight cutoffs may vary by label and country, so clinicians rely on local guidance and product labeling [10] [6] [4].