NEWS

Experts Warn Against Using Ivermectin to Treat COVID-19

A medication label that reads "Ivermectin 3 mg tablet" with 3 white tablets on it.

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Key Takeaways

  • Experts are warning that there is not enough evidence to support using a drug called ivermectin to treat COVID-19.
  • Ivermectin is used to treat parasitic worms. Some forms of ivermectin are intended for animals and are not safe for humans to consume.
  • According to the NIH, FDA, and WHO, studies on using ivermectin to treat COVID-19 have been inconclusive so far.

An unlikely drug is gaining attention as a potential treatment for COVID-19, but experts are warning against its use.

Interest in ivermectin, an inexpensive medication typically used to treat parasitic infections in both humans and animals, as a COVID-19 “miracle drug” began in June 2020 when a study found that it could reduce the viral replication of SARS-CoV-2 in vitro—or outside of a living organism.

What Is Ivermectin?

Ivermectin is a drug approved by the FDA to treat conditions caused by parasitic worms like strongyloidiasis and onchocerciasis (river blindness). It's typically an oral medication taken as a single dose, but topical formulations can be used for head lice or rosacea.

However, there is no conclusive data showing that ivermectin is effective at killing viruses inside the human body. And experts, including the Food and Drug Administration (FDA), are warning against its use for COVID-19.

Ivermectin for Animals

Ivermectin is not a new drug—Inci Yildirim, MD, PhD, a vaccinologist and pediatric infectious disease specialist at Yale Medicine and an associate professor of medicine and global health at the Yale School of Medicine, tells Verywell that it's been used in humans "since the early 1980s," and "has been on the veterinary market even longer for almost half a century."

Ivermectin was labeled as a “wonder drug” before COVID-19 because of its ability to treat parasitic infections, especially river blindness, which caused significant social and economic burdens in certain communities in Africa and South America.

People with pets are probably more familiar with the forms of ivermectin that are used to prevent heartworm disease and certain parasites. It's crucial for people to understand that the form of the drug used for their pets is not meant or safe for humans to take.

“Animal ivermectin products are usually highly concentrated and they include other ingredients that can be very dangerous for the human body,” Yildirim says. “We should not self-medicate with ivermectin intended for animals such as horses or cows. Doses approved to be safe and effective in humans are different from the doses used in animals.”

The FDA reports cases of people who required medical support and even hospitalization after taking ivermectin medications intended for horses.

No Evidence to Support Ivermectin for COVID

In the earlier phases of the pandemic, there were no FDA-approved COVID-19 treatments or vaccines. Many potential treatments were on researchers' radar, and ivermectin was among them.

“During that time, a group of researchers from Australia reported that ivermectin was reducing the viral replication in their experiment using cell cultures—in vitro, not in an animal or a human being—and suggested it warrants further investigation for possible treatment effect,” Yildirim says.

The FDA, the National Institutes of Health (NIH), and the World Health Organization (WHO), currently state that there is insufficient data on the use of ivermectin to treat COVID-19 patients.

Merck, the company that makes ivermectin, also states that there is no evidence of the drug's therapeutic effect against COVID-19.

Lab Results Don't Always Translate to Human Use

Even though researchers found ivermectin slowed the replication of SARS-CoV-2, the virus that causes COVID-19, in a lab, that finding may not hold true within the body.

Nasia Safdar, MD, PhD, professor of infectious diseases at the University of Wisconsin School of Medicine and Public Health, tells Verywell that a dosage that works in a lab does not necessarily reflect the dose needed in humans, which might be too high to achieve safely.

Sharon Nachman, MD

Natural remedies sound nice, but there is no science or clinical trial data behind them, just personal attestations and strong feelings.

— Sharon Nachman, MD

“Think of it as a big hammer on a plate," Sharon Nachman, MD, chief of the Division of Pediatric Infectious Diseases at Stony Brook Children’s Hospital in New York, tells Verywell. "Yes, you broke the plate, but you also destroyed the table and sent splinters all over the room. We don’t want that kind of approach to guide us when we think a medication is ready for use in humans."

Nachman agrees with Safdar, adding that "it is but the earliest step and rarely results in efficacy in humans. Far too often these types of ‘effects’ are too lethal or too toxic to humans and the drug never moves past the petri dish stage.”

Inconclusive Studies

While there have been, and currently are, studies evaluating the use of ivermectin to treat COVID in humans, the results are not conclusive.

A 2020 review suggested that the ivermectin doses used for inhibiting SARS-CoV-2 are not attainable in humans. A 2021 study published in JAMA Network in March showed that giving a five-day course of ivermectin to adult patients with mild COVID-19 did not reduce the duration of their symptoms.

“Many other studies after [the initial in vitro research], including the randomized clinical trials where COVID-19 patients were given ivermectin, and outcomes were compared to other treatment options, there was no benefit or worsening of disease after ivermectin use,” Yildirim says. “Some studies showed patients who took ivermectin cleared the virus faster, but it didn’t have any impact on the resolution of the symptoms.”

What This Means For You

Ivermectin is approved by the FDA to treat conditions like strongyloidiasis and onchocerciasis. However, no data currently proves that it can treat COVID-19. To avoid harm, you should not take any unapproved COVID-19 medications or treatments.

Why Are People Turning to Ivermectin?

“Natural remedies sound nice," Nachman says. "But there is no science or clinical trial data behind them, just personal attestations and strong feelings."

Nachman points to fear and uncertainty around COVID vaccination as a possible factor driving the interest in ivermectin.

“There is a lot of vaccine hesitancy regarding COVID-19 vaccines," Nachman says. "However, as someone who has seen so many adults with COVID-19 in the hospital and too often dying from COVID-19, or suffering from symptoms that last way beyond their initial illness, I can only say that the illness is real and that prevention is the only way that we will get past this pandemic."

Safdar says that some people are choosing to self-medicate and forgo COVID-19 vaccination because of the misinformation about the pandemic and mistrust in the vaccine.

Goals of Future Research

The NIH has acknowledged published studies and randomized trials investigating the use of ivermectin in COVID-19 patients. However, it emphasizes that no conclusive verdict can be made on the drug's clinical benefit because the studies had significant limitations.

Limitations of Ivermectin Research

The research on ivermectin for treating COVID thus far has limitations, including:

  • Small sample sizes for most studies
  • Varied ivermectin dosage and schedule
  • Some trials were open-label (the participants and investigators knew which treatments were given)
  • Subjects were taking other medications at the time of the study (which can affect results)
  • COVID-19 severity in participants was not described well
  • Some studies did not have well-defined outcome measures

Safdar says that well-designed clinical trials will be needed to evaluate the use of ivermectin in relation to COVID-19—some of which are in progress already. While this is encouraging, it's important to hold these studies to a rigorous standard.

Researchers hope that the results of the current and future clinical trials will provide conclusive data on the use of ivermectin for COVID-19.

For now, avoid unconventional and unapproved treatments that can cause serious harm. Instead, focus on the safe and effective tools that we have and know work: wear a face mask, social distance, and get a COVID-19 vaccine.

"We now have more than one safe and effective vaccine against SARS-CoV-2," Yildirim says. "We know that social distancing, wearing your mask, and washing your hands frequently are very effective ways to limit the spread of COVID-19.”

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

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6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Caly L, Druce JD, Catton MG, et al. The FDA-approved drug ivermectin inhibits the replication of SARS-CoV-2 in vitro. Antiviral Res. 2020;178:104787. doi: 10.1016/j.antiviral.2020.104787.

  2. Food & Drug Administration (FDA). Why You Should Not Use Ivermectin to Treat or Prevent COVID-19. Updated March 5, 2021.

  3. Merck. Merck Statement on Ivermectin use During the COVID-19 Pandemic. Updated February 4, 2021.

  4. Momekov G, Momekova D. Ivermectin as a potential COVID-19 treatment from the pharmacokinetic point of view: antiviral levels are not likely attainable with known dosing regimens. Biotechnology & Biotechnological Equipment. 2021;34(1):469-474. doi:10.1080/13102818.2020.1775118

  5. López-Medina E, López P, Hurtado IC, et al. Effect of Ivermectin on Time to Resolution of Symptoms Among Adults With Mild COVID-19: A Randomized Clinical Trial. JAMA Network. 2021;325(14):1426–1435. doi:10.1001/jama.2021.3071

  6. National Institutes of Health (NIH). Ivermectin. Updated February 11, 2021.

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