Some still tout ivermectin as a cure-all. Here’s what the science says

In early 2020, as the U.S. recorded its first confirmed COVID-19 cases and the scale of the unfolding pandemic came into focus, scientists and clinicians around the world raced to understand the unfamiliar virus. Researchers immediately started testing whether existing drugs — such as ivermectin, chloroquine, even the diabetes drug metformin — could be repurposed to treat the rapidly-spreading SARS-CoV-2. 

At the time, a growing body of evidence suggested that ivermectin, a drug primarily used to kill parasites, might also be an effective antiviral. Previous studies suggested that ivermectin might quell infections caused by all sorts of viruses: chikungunya, yellow fever, West Nile, Zika.

In April — one month after the World Health Organization declared COVID-19 a global pandemic — Australian researchers reported that a single dose of ivermectin successfully killed SARS-CoV-2 in a petri dish within 48 hours. 

Early studies showed antiviral activity in vitro — meaning in isolated cells under artificial conditions — but they did not establish whether ivermectin could safely or effectively treat COVID-19 in people. 

The battle over ivermectin was only just beginning. 

The COVID-19 “miracle drug” 

As the pandemic accelerated, proven treatments remained scarce. When the first medication — remdesivir — was approved in October 2020, the U.S. had recorded more than 7 million cases and 200,000 deaths. By the time the first vaccines became available outside of clinical trials in December, the case count had surpassed 13 million and the death toll had climbed to nearly 300,000.

By then, at least a dozen clinical trials and other studies — some of which were published without undergoing the typical peer review process — had found that ivermectin could treat COVID-19. These early signals were amplified through social media and nontraditional media channels, creating the impression that ivermectin was being overlooked or suppressed. 

Michael Rose remembers that moment well. After graduating from medical school in 2019, Rose was working as a physician intern at Johns Hopkins when the pandemic began. He was among the many clinicians and researchers who conducted clinical trials to test ivermectin as a COVID-19 treatment.

“It was something we saw quickly became politicized and polarized,” Rose told Straight Arrow News. “It kind of had this cult following that developed during the pandemic.”

Some physicians and researchers began publicly advocating for the use of ivermectin, framing the drug as a low-cost, readily available solution amid institutional caution and slow-moving clinical guidance. In December, Pierre Kory, a physician and founder of the non-profit then called the Front Line COVID-19 Critical Care Alliance, testified about ivermectin’s effectiveness in front of the Senate Committee on Homeland Security and Governmental Affairs. 

“We now have data from over 20 well-designed clinical studies, 10 of them randomized, controlled trials, with every study consistently reporting large magnitude and statistically significant benefits in decreasing transmission rates, shortening recovery times, decreasing hospitalizations or large reductions in deaths,” Kory said.

“These data show that ivermectin is effectively a ‘miracle drug’ against COVID-19,” he told Senators. 

He criticized the U.S. pandemic response efforts for being too focused on vaccines and high-cost pharmaceutical treatments while neglecting research and guidance on early, at-home and preventative COVID-19 therapies. Over time, Kory became a prominent ivermectin proponent. Then, in 2024, the American Board of Internal Medicine (ABIM) revoked Kory’s board certification in critical care, pulmonary disease and internal medicine, according to multiple news reports. The move amounted to what Kory saw as an “attack on freedom of speech.”  

Board certification is a voluntary credential that shows a physician has expertise in a speciality; physicians can still practice medicine without one as long as they retain their medical license.

ABIM told SAN that its confidentiality policy does not allow the organization to discuss individual physicians; however, ABIM’s website states that as of January 2026, Kory’s certifications are revoked.

As early as mid-2021, patients who were unable to get ivermectin from their doctors purchased the livestock version of the medication from farm supply stores.

The Trump administration gave way to the Biden administration which, in September 2021, enacted strict vaccine mandates for federal workers, health care staff, military servicemembers and large companies. The pandemic became increasingly politicized, and ivermectin became a symbol in wider disputes over the government’s response, as well as trust in public health authorities, pharmaceutical companies and vaccines. Some podcasts, talk shows and online platforms gave prominent airtime to ivermectin proponents. 

While the ivermectin controversy played out in the media, scientists around the world ran rigorous clinical trials to see if the “miracle drug” might be a suitable treatment for COVID-19 infections. 

Today, hundreds of scientific papers have been written about ivermectin: Some promote the drug; others strongly urge against its use. The Food and Drug Administration has not approved the drug for treating COVID-19. (The Department of Health and Human Services did not respond to multiple requests for comment.) Yet some clinicians still swear it is effective and continue offering ivermectin to patients. 

SAN analyzed 39 clinical trials published in more than a dozen scientific journals to shed new light on a persisting question: What, if any, consensus was ever reached on whether ivermectin is an effective treatment for COVID-19?

What is ivermectin?

Ivermectin is a medication used to treat several parasitic diseases caused by intestinal worms, as well as head lice and rosacea. 

The drug was first discovered in the 1970s by Japanese scientist Satoshi Ōmura, and later refined into a safer version for human use by scientists at Merck. In the 1980s, Merck agreed to manufacture ivermectin and donate it to countries where it could be used to treat onchocerciasis, also known as river blindness, which affected roughly 20 million people at the time. 

Ivermectin was considered a wonder drug, so safe and effective for controlling several tropical diseases that it is given en masse to entire communities. Today, it is FDA-approved as an antiparasitic drug, and hundreds of millions of people around the world take ivermectin once or twice a year. 

A review of the evidence

SAN searched the National Library of Medicine’s database of scientific articles for previous studies assessing whether ivermectin effectively treated COVID-19. SAN identified 39 randomized controlled trials conducted across 21 countries. Considered the gold standard of research, this type of experiment randomly assigned patients to receive ivermectin, a placebo or, in some studies, a different treatment plan altogether. 

Although all were randomized controlled trials, each study varied slightly. 

Some enrolled people with mild COVID-19, others focused on hospitalized or higher-risk patients and a few targeted specific groups such as people with obesity. Trials used different ivermectin dosing regimens and treatment schedules and measured different outcomes, including severity of illness, symptom duration or viral clearance in blood or nasal samples. 

Thirty-five studies investigated whether ivermectin was an effective treatment for people already infected with COVID-19. Four others assessed if the drug could prevent infection for healthy people. 

Of the 35 studies that tested ivermectin as a treatment for COVID-19 patients, 21 found that the antiparasitic drug was no more effective than a placebo.

In a study of more than 3,500 patients in Brazil, researchers reported that a three-day course of ivermectin did not prevent hospitalization or emergency room visits among higher-risk adults with early COVID-19 symptoms. 

In a separate U.S. trial of just under 1,600 adults with early mild to moderate COVID-19, a three-day course of ivermectin did not significantly shorten symptom duration, recovery time or reduce hospitalization or death. The median recovery time was 12 days in the ivermectin group and 13 days in the placebo group. Meanwhile, there were 10 hospitalizations or deaths in the ivermectin group and 9 in the placebo group.

While the majority of studies found that ivermectin was not effective against COVID-19 infections, five trials reported that it was. The studies were conducted in Bangladesh, Argentina, Egypt, Iran and Nigeria. All the studies enrolled fewer than 400 people. 

In an Egyptian clinical trial with 114 patients, the 57 people with mild COVID-19 who used an ivermectin nasal spray twice daily cleared the virus about four days sooner and had shorter durations of several symptoms than the 57 study participants who did not receive the spray. 

A separate study that enrolled 69 hospitalized COVID-19 patients in Iran found that a single dose of ivermectin also shortened hospital stay and duration of symptoms. Persistent cough lasted for about three days among patients who received ivermectin, compared with just under five days for patients who did not. On average, the patients who received ivermectin remained in the hospital for seven days; patients who did not receive ivermectin stayed for eight. 

The other nine studies reviewed by SAN reported mixed results; ivermectin improved some outcomes but did not affect others.

Ivermectin may help prevent COVID-19 infection

Four of the 39 studies SAN reviewed tested whether ivermectin could prevent COVID-19 infection. In these studies, researchers randomly gave some participants ivermectin while other participants either received a placebo or no treatment at all. 

Three of the four studies found that the drug was successful as a preventive treatment. 

One study in Egypt enrolled 304 family members and others who had close contact with a person infected with coronavirus. Of the 203 people who were given ivermectin, only 15 went on to develop a COVID-19 infection themselves. Meanwhile, 59 of the 101 close contacts that received no treatment developed COVID-19. People who did not receive ivermectin were roughly 11 to 12 times more likely to become infected than participants who did receive it, the researchers summarized.

In another study, researchers in Singapore studied healthy migrant workers who were quarantined in a multi-story dormitory. Residents of different floors were randomly selected to receive different prevention treatments: ivermectin, hydroxychloroquine, vitamin C or other drug regimens. The study participants who received ivermectin did not report any excessive side effects; however, the drug did not prevent COVID-19 infections compared with vitamin C drops.

Other studies

In 2020, at least eight Latin American countries distributed COVID-19 kits to citizens to help prevent and treat infections and avoid overwhelming the health system. These kits contained everything from vitamins to cough suppressants and fever reducers. Many also contained ivermectin. Researchers jumped at the chance to study whether the mass distribution of ivermectin altered the course of the pandemic in those countries.

Many of the resulting studies reported that ivermectin helped reduce excess deaths. In one study, researchers estimated that ivermectin medical kits reduced hospitalization by more than 50% in Mexico City. In another, authors reported that excess deaths among older Peruvians dropped by about 74% within a month of local governments distributing ivermectin kits. Within two months of a new president being elected and subsequently restricting ivermectin use, excess deaths increased 13-fold nationwide, according to scientists.

These observational studies are not as tightly controlled as randomized controlled trials. 

In time, at least three countries halted the distribution of ivermectin, citing a lack of evidence supporting the drug’s use for COVID-19. 

Ivermectin for COVID-19

Although the majority of randomized controlled trials suggest that ivermectin is not an effective treatment for COVID-19 infections, some physicians still prescribe the drug.

Eli Schwartz, a professor and physician at the Center for Geographic Medicine in Israel, is one of them.

Schwartz told SAN that he believes ivermectin is an effective drug, but that the pharmaceutical industry does not want to push an old, cheap drug when it could make more money pushing something new. 

“The bottom line is that we can say that in Western countries, especially those who are influenced by the United States, ivermectin is not in use, and many studies have shown that there is not any benefit from it,” he said.

“If you ask me, I would say definitely ivermectin has an effect on the virus, on the COVID virus, and I would say that non-scientific powers are led to kick it out,” Schwartz explained. 

Physicians who promoted ivermectin in the U.S. faced disciplinary action and lawsuits; some, like Kory, lost board certifications. Medical journals, Schwartz said, would not publish studies that found ivermectin had a positive impact on COVID-19 infections. It took Schwartz more than a year to publish the results of his own randomized trial, he told SAN.

Schwartz also pointed out that scientists, lawmakers and even Merck, the manufacturer of ivermectin, were quick to say that ivermectin was dangerous even though an overwhelming body of evidence proved otherwise.

Rose, now a research fellow in Johns Hopkins’ clinical pharmacology department, told SAN he sees things differently.

“We’ve done a pretty thorough and exhaustive job on studying ivermectin and COVID in a number of different settings, etc, and so I wouldn’t say there’s more research that needs to be done,” he said. 

However, Rose did agree with Schwartz’s point that ivermectin is safe.

“When given at typical doses, it’s incredibly safe. Anyone who says other than that is also being disingenuous,” he said.

Still, he said, there is a potential for harm if patients take ivermectin instead of other, evidence-based treatments.

Ivermectin’s cult-like following persists

Since the height and fallout of the COVID-19 crisis, the ivermectin following has “spilled over into many other disease states,” Rose said. Some clinicians, celebrities and politicians have promoted ivermectin as a treatment for anything from Lyme disease and HIV to Alzheimer’s and multiple sclerosis. Oncologists say interest in ivermectin for treating cancer has “spread like wildfire.”

After Mel Gibson discussed how ivermectin — and other antiparasitic drugs — cured several of his friends of cancer on the popular podcast “The Joe Rogan Experience,” Florida lawmakers allocated a portion of $60 million in new cancer research funding towards ivermectin studies.

Several studies done with petri dish cells or animal models have shown that ivermectin can slow cancer growth and improve the immune system’s ability to recognize and target tumors. There are a handful of ongoing clinical trials exploring a cancer treatment that involves ivermectin alongside immunotherapies. 

Many of Rose’s oncology colleagues say patients constantly inquire about taking ivermectin. Survey data backs this up; one poll found that more than 90% of oncologists had been asked about ivermectin by patients or their family members. When Rose’s father recently went through chemotherapy treatment, family members asked whether ivermectin could help. 

“If someone takes ivermectin in addition to chemotherapy, it is not a real big deal,” he told SAN. “If someone takes ivermectin instead of chemotherapy, then it’s a very, very big deal.”

Future research might one day support ivermectin as an effective treatment for cancer and other diseases, but at this time, the scientific evidence does not. 

Today, the ivermectin saga is no longer just about a drug. It has become a case study in the erosion of trust in the nation’s science and public health institutions. Pandemic messaging was inconsistent, opaque and often dismissed uncertainty. As scientists sought consensus via research, public consensus drifted further from reach. Now, ivermectin remains a divisive symbol in a broader conversation about medical freedom.