People Are Taking a Deworming Drug Meant for Animals to Treat COVID, and the FDA Warns This Is a Bad Idea


Messaging from government agencies tends to be a little dry, but the US Food and Drug Administration dropped a hilarious tweet that has plenty of people talking.

"You are not a horse. You are not a cow. Seriously, y'all. Stop it," the tweet reads, before linking to a page about why people shouldn't use the animal deworming medication ivermectin to treat COVID-19.

People had a field day in the comments. But seriously, is this really happening, and why? Here's what you need to know about ivermectin—and all the reasons you really shouldn't take this when you have COVID-19 or almost any other illness, either.

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Why Are People Taking Ivermectin? Explainer , Closeup image of woman face and pill in hand Why Are People Taking Ivermectin? Explainer , Closeup image of woman face and pill in hand to treat people with intestinal strongyloidiasis and onchocerciasis, two conditions that are caused by parasitic worms. Some forms of ivermectin are also used to treat external parasites like head lice, as well as for skin conditions like rosacea.

Some kinds of ivermectin are used in animals to prevent heartworm disease, along with select internal and external parasites. However, the FDA points out, those are different from the types of ivermectin used in people and are safe only when they're prescribed for animals.

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OK, so why are people using ivermectin to treat COVID-19?

It's not entirely clear, but it could have something to do with a recent study that described the effect of ivermectin on SARS-CoV-2, the virus that causes COVID-19, in a lab setting. That study, published in the journal Antiviral Research in June, found that a single treatment of ivermectin in a lab caused a 5,000-fold reduction in SARS-CoV-2 at 48 hours in a cell culture. "Ivermectin therefore warrants further investigation for possible benefits in humans," the researchers concluded.

But other studies on ivermectin have either been deemed low quality or found that ivermectin didn't have an impact on the duration of illness in people with mild forms of COVID-19, including a study of 400 patients published in JAMA.

"The studies that are rigorous have shown that ivermectin is not worth the paper it's written on when it comes to treating COVID-19," William Schaffner, MD, an infectious disease specialist and professor at the Vanderbilt University School of Medicine, tells Health.

"There is no strong evidence that ivermectin is beneficial for the treatment of COVID and the studies that exist are not very rigorous," Amesh A. Adalja, MD, a senior scholar at the Johns Hopkins Center for Health Security, tells Health.

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Is it safe to use ivermectin to treat COVID-19?

One of the bigger issues here is that people are buying ivermectin that's intended for animals and using it on themselves or loved ones, which is a problem. Ivermectin for animals, the FDA says, "should only be given to animals for approved uses or as prescribed by a veterinarian in compliance with the requirements for extra-label drug use."

There are approved uses for ivermectin in people and in animals, but they're different. Meaning, you shouldn't take pills approved for dogs and vice versa.

If you take ivermectin, the FDA says you could end up dealing with some potential side effects, including:

  • Skin rash
  • Nausea
  • Vomiting
  • Diarrhea
  • Stomach pain
  • Facial or limb swelling
  • Dizziness
  • Seizures
  • Confusion
  • Sudden drop in blood pressure
  • Liver injury

"Taking ivermectin and not getting vaccinating or delaying medical care could be dangerous," Dr. Adalja says. If you're on another medication and you take ivermectin, you could also face a potentially serious drug interaction, Thomas Russo, MD, professor and chief of infectious disease at the University at Buffalo in New York, tells Health. "There is no data to support that it works," he says. "It's best not to take it."

Dr. Schaffner understands that people are frustrated because a good treatment for COVID-19 doesn't exist yet. "It stands to reason that all of us want to treat COVID," he says. "If we had a medication that worked, people would all use it. But the reason for not using it is that it doesn't work. There aren't isolated people out there who know about this and others don't."

If you have COVID or suspect you do, don't waste your time with ivermectin, whether it was prescribed for humans or animals. Instead, get in touch with your doctor, who can assess your next steps.

The information in this story is accurate as of press time. However, as the situation surrounding COVID-19 continues to evolve, it's possible that some data have changed since publication. While Health is trying to keep our stories as up-to-date as possible, we also encourage readers to stay informed on news and recommendations for their own communities by using the CDCWHO, and their local public health department as resources.

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