Ivermectin is an antiparasitic drug that is well established for use in animals and people. The World Health Organization (WHO), the European Medicines Agency (EMA), the United States Food and Drug Administration (FDA), and the Infectious Diseases Society of America (IDSA) all do not advise using ivermectin in an attempt to treat or prevent COVID-19.
Early in the COVID-19 pandemic, laboratory research suggested ivermectin might have a role in preventing or treating COVID-19. Online misinformation campaigns and advocacy boosted the drug's profile among the public. While scientists and physicians largely remained skeptical, some nations adopted ivermectin as part of their pandemic-control efforts. Some people, desperate to use ivermectin without a prescription, took veterinary preparations, which led to shortages of supplies of ivermectin for animal treatment. The FDA responded to this situation by saying "You are not a horse. You are not a cow. Seriously, y'all. Stop it", in a tweet to draw attention to the issue, for which they were later sued by three ivermectin-prescribing doctors.
Subsequent research failed to confirm the utility of ivermectin for COVID-19, and in 2021 it emerged that many of the studies demonstrating benefit were faulty, misleading, or fraudulent. Nevertheless, misinformation about ivermectin continued to be propagated on social media and the drug remained a cause célèbre for anti-vaccinationists and conspiracy theorists. This spread to conspiracy theorists further asserting that ivermectin could treat all diseases.
Research Some in vitro drug screening studies early in the pandemic showed that ivermectin has antiviral effects against several distinct positive-sense single-strand RNA viruses, including SARS-CoV-2. Subsequent studies found that ivermectin could inhibit replication of SARS-CoV-2 in monkey kidney cell culture with an IC50 of 2.2–2.8 μM.
However, doses much higher than the maximum approved or safely achievable for use in humans would be required for an antiviral effect while treating COVID-19. Aside from practical difficulties, such high doses are not covered by current human-use approvals of the drug and may be toxic, as the antiviral mechanism of action is believed to be via the suppression of a host cellular process, specifically the inhibition of nuclear transport by importin α/β1. Several other drugs which inhibit importin α/β1 at therapeutic doses have failed clinical trials due to systemic toxicity and a narrow therapeutic window.
To resolve uncertainties from previous small or poor-quality studies, , large scale trials were underway in the United States and the United Kingdom. A large randomised controlled trial ACTIV-6, published in October 2022, found ivermectin was not effective as a COVID-19 treatment.
Research limitations, ethics and fraud Many studies on ivermectin for COVID‑19 have serious methodological limitations, resulting in very low evidence certainty. Several publications that supported the efficacy of ivermectin for COVID‑19 have been retracted due to errors, unverifiable data, and ethical concerns.
Several high-profile publications purporting to demonstrate reduced mortality in COVID-19 patients were later retracted due to suspected data falsification. This only added to confusion among the media and lay public, as these publications had been widely cited by ivermectin supporters and included in meta-analyses.
In January 2022, 22 inmates at the Washington County Detention Center in Arkansas filed a lawsuit over hundreds of ivermectin pills given to them as "vitamins" in 2020.
In February 2022, the American Journal of Therapeutics issued expressions of concern against two positive systematic reviews of ivermectin for COVID-19 which it had published in 2021, because of suspicions about the underlying data that would undermine these papers' findings of benefit.
In Mexico City the government distributed ivermectin widely as a COVID-19 treatment and published the observed results on the SocArXiv archive as a research paper. The paper was subsequently withdrawn by the archive citing concerns that it was unethical, as it effectively was an experiment carried out on people without gaining informed consent. Philip N. Cohen of the SocArXiv steering committee said "the article is of very poor quality or deliberately false and misleading" and that its removal was justified to prevent public harm.
Clinical guidance In February 2021, Merck, the developer of the drug, issued a statement saying that there is no good evidence ivermectin is effective against COVID‑19 and that attempting such use may be unsafe. After reviewing the evidence on ivermectin, the European Medicines Agency (EMA) advised against its use for prevention or treatment of COVID‑19 and that "the available data do not support its use for COVID‑19 outside well-designed clinical trials." Consequently, ivermectin is not authorized for use to treat COVID‑19 within the European Union. Ivermectin is not approved by the U.S. Food and Drug Administration (FDA) for use in treating any viral illness, and the U.S. National Institutes of Health COVID‑19 Treatment Guidelines state that there is insufficient evidence for ivermectin to allow for a recommendation for or against its use. In the United Kingdom, the national COVID‑19 Therapeutics Advisory Panel determined that the evidence base and plausibility of ivermectin as a COVID‑19 treatment were insufficient to pursue further investigations. In November 2023, the WHO updated its treatment guidelines to recommend strongly against the use of ivermectin as a COVID-19 treatment, due to a lack of research evidence or biological plausibility. The Brazilian Health Regulatory Agency, Brazilian Society of Infectious Diseases, and Brazilian Thoracic Society issued position statements advising against the use of ivermectin for prevention or treatment of early-stage COVID‑19.
COVID-19 and strongyloidiasis There is one very specific circumstance in which ivermectin may be useful in the management of COVID-19. People infected with the Strongyloides stercoralis parasite are at risk for strongyloides hyperinfection syndrome (SHS) — a condition with a mortality rate as high as 90% — if given corticosteroids to treat COVID-19. Strongyloidiasis affects as many as 370 million people worldwide, and it is usually subclinical or even asymptomatic. However, it can become fatal in the setting of SHS, which can be triggered by the immunosuppression that results from the administration of corticosteroids. In fact, multiple cases of SHS have been reported after the use of corticosteroids in the management of COVID-19 pneumonia. For this reason, the World Health Organization (WHO), the European Centre for Disease Prevention and Control (ECDC), the Public Health Agency of Canada (PHAC) and the United States Centers for Disease Control and Prevention (CDC) all recommend presumptive treatment for strongyloidiasis with ivermectin in people at high or moderate risk of SHS before or in conjunction with corticosteroids in the management of COVID-19. People who were born, resided, or had long-term travel in Southeast Asia, Oceania, sub-Saharan Africa, South America, or the Caribbean are considered to be at high risk for SHS, while people from Central America, Eastern Europe, the Mediterranean, Mexico, Middle East, North Africa, and the Indian subcontinent are considered to be at moderate risk. In such cases, ivermectin is a treatment for strongyloidiasis, not for COVID-19.
Regulatory status and off-label use
Misinformation, lower degrees of trust, and a sense of despair over increasing case and death counts have led to an increase in ivermectin's use in Central and Eastern Europe, Latin America, and South Africa. A black market has also developed in many of these countries where official approval has not been granted.
The viral social media misinformation about ivermectin has gained particular attention in South Africa where an anti-vaccination group called "South Africa Has A Right To Ivermectin" has been lobbying for the drug to be made available for prescription. Another group, the "Ivermectin Interest Group" launched a court case against the South African Health Products Regulatory Authority (SAHPRA), and as a result a compassionate use exemption was granted. SAHPRA stated in April 2021 that "At present, there are no approved treatments for COVID-19 infections." In September 2021, SAHPRA repeated warnings against fake news and misinformation and took up the FDA's stance about ivermectin. Due to lacking evidence of efficacy and growing body of retracted pro-ivermectin papers, SAHPRA revoked the compassionate use program in May 2022.
Despite the absence of high-quality evidence to suggest any efficacy and advice to the contrary, some governments have allowed its off-label use for the prevention and treatment of COVID‑19. Countries that have granted such official approval for ivermectin include the Czech Republic, Slovakia, Mexico, Peru (later rescinded), India (later rescinded), and the Philippines. Cities that have launched campaigns of massive distribution of ivermectin include Cali, Colombia; and Itajai, Brazil.
In Arkansas in 2021, a prison doctor prescribed ivermectin for inmates without their consent. A legal action brought on the inmates' behalf by the American Civil Liberties Union (ACLU) was settled with the prison authorities paying compensation. The ACLU said the outcome was "victory for civil rights and medical ethics".
Ivermectin is not approved by the U.S. Food and Drug Administration (FDA) for use in treating any viral illness and is not authorized for use to treat COVID-19 within the European Union. After reviewing the evidence on ivermectin, the EMA said that "the available data do not support its use for COVID-19 outside well-designed clinical trials". The World Health Organization also said that ivermectin should not be used to treat COVID-19 except in a clinical trial. The Brazilian Health Regulatory Agency, Brazilian Society of Infectious Diseases, and Brazilian Thoracic Society issued position statements advising against the use of ivermectin for prevention or treatment of early-stage COVID-19.
Several Latin American government health organizations recommended ivermectin as a COVID-19 treatment based, in part, on preprints and anecdotal evidence; these recommendations were later denounced by the Pan American Health Organization.
In the United States, an analysis of prescribing data suggested the influence of political affiliation, as Republican-voting areas saw a pronounced surge in ivermectin (and hydroxychloroquine) prescription in 2020. As of June 2025, legislation to make the drug available over-the-counter has passed in four US states.
Human use of veterinary products
As people began using veterinary preparations of ivermectin for personal use stocks began to decline, requiring vendors to ration their sales and raise prices. In the United States supplies of horse dewormer paste began to run low as people used it for themselves; some vendors required their customers to show a picture of themselves and their horses together, to provide assurance they were purchasing the paste for animal use.
In August 2021 the CDC issued a health alert prompted by a sharp rise in calls to poison control centres about ivermectin poisoning. The CDC described two cases requiring hospitalization; in one, a person had drunk an injectable ivermectin product intended for use in cattle.