Ivermectin does not cure COVID-19. Multiple large clinical trials have tested the drug against placebo, and none found a meaningful benefit for preventing hospitalization, speeding recovery, or reducing death. The FDA has not authorized or approved ivermectin for preventing or treating COVID-19, and a comprehensive Cochrane review of the available evidence concluded there is no evidence to support its use for this purpose.
What the Largest Trials Found
Three major randomized trials tested ivermectin against placebo or usual care in thousands of COVID-19 patients. Their results were consistent: ivermectin performed no better than a sugar pill on the outcomes that matter most.
The TOGETHER trial, published in the New England Journal of Medicine, enrolled 679 ivermectin patients and 679 placebo patients in Brazil. About 14.7% of those taking ivermectin ended up hospitalized or in an emergency department, compared with 16.3% on placebo. That small numerical difference was well within the range of chance, with a relative risk of 0.90 and a confidence interval that crossed 1.0, meaning the drug showed no statistically meaningful effect.
The ACTIV-6 trial, a U.S. government-funded study published in JAMA, randomized 1,432 outpatients across 93 sites. Median time to recovery was 11 days with ivermectin and 12 days with placebo. The hazard ratio was 1.02, essentially identical. Hospitalization and emergency visit rates were also nearly the same: 5.5% with ivermectin versus 5.8% with placebo.
The PRINCIPLE trial, a large UK platform trial, did find that self-reported recovery came about two days sooner with ivermectin (14 days versus 15 days median). However, the probability that this represented a “meaningful” benefit by the trial’s own predefined threshold was only 19%, far below what researchers would consider convincing. More importantly, hospitalization and death rates were identical between the two groups, and the trial stopped enrolling ivermectin patients due to futility.
Why Early Lab Results Were Misleading
The ivermectin hypothesis started in April 2020, when Australian researchers showed the drug could stop SARS-CoV-2 from replicating in a lab dish. That finding was real, but it came with a critical caveat: the concentration needed to kill the virus in a petri dish was far higher than what the human body can safely achieve with approved doses. Ivermectin inhibits the virus at micromolar concentrations, and standard human dosing doesn’t come close to producing those levels in lung tissue or blood. In short, what works in a test tube doesn’t always work in a person, and this turned out to be one of those cases.
Flawed Studies That Fueled the Hype
Early in the pandemic, several smaller studies appeared to show dramatic benefits from ivermectin. These studies were widely shared online and drove enormous public interest. The problem was that many of them had serious flaws.
The most influential was a large Egyptian study that claimed ivermectin sharply reduced COVID-19 deaths. It was later retracted after a medical student discovered plagiarized text and glaring problems in the raw data. Roughly a third of patients recorded as dying from COVID-19 in the dataset had death dates before the study even began recruiting. About 25% of participants appeared to have been hospitalized before enrollment started. The preprint server pulled the paper, stating its conclusions were “compromised.” Because several early meta-analyses (studies that pool results from multiple trials) had included this data, their positive conclusions about ivermectin collapsed once the fraudulent study was removed.
Risks of Self-Medicating With Ivermectin
Ivermectin is a legitimate, Nobel Prize-recognized drug for treating parasitic infections like river blindness and strongyloidiasis. At approved doses for those conditions, it’s generally well tolerated. The danger comes from people taking unapproved doses or using veterinary formulations intended for horses or cattle.
Animal ivermectin products contain the same active ingredient but come in highly concentrated pastes or injectables designed for animals weighing hundreds or thousands of pounds. These formulations are not tested for human safety, and dosing errors are easy to make. Overdose symptoms range from nausea, vomiting, and diarrhea to far more serious neurological effects: confusion, hallucinations, tremors, seizures, loss of balance, and coma. In one published case, a 52-year-old man who self-medicated with high-dose ivermectin for COVID symptoms developed visual hallucinations, restlessness, and decreased consciousness.
Where the Evidence Stands Now
The Cochrane Collaboration, which produces the gold standard of medical evidence reviews, updated its analysis of ivermectin for COVID-19 and found “no evidence to support the use of ivermectin for treating COVID-19 or preventing SARS-CoV-2 infection.” For outpatients specifically, the certainty of evidence ranged from low to high that ivermectin provides no beneficial effect.
The FDA’s position, updated as of April 2024, is straightforward: available clinical trial data do not demonstrate that ivermectin is effective against COVID-19 in humans. The agency has neither authorized nor approved it for this use. Proven COVID-19 treatments, including antiviral medications and updated vaccines, remain the recommended options for preventing severe illness.