Pros and Cons: Giddy Up on Ivermectin?


Editor-In-Chief Salim R. Rezaie, MD debates Senior Board member William Sullivan, DO, JD, on the use of Ivermectin in treating COVID-19.

Just Say No to Ivermectin for COVID-19


Throughout the COVID-19 pandemic, numerous therapeutic agents have been repurposed and applied empirically and within clinical trials.  Prophylactic medications for COVID-19 could have a huge benefit, but studies to date haven’t panned out.  Initially many therapeutic medications were used late in illness, and one of the criticisms of these negative studies was that the drugs were applied too late in the disease and therefore didn’t have any potential for benefit.

There were also numerous studies showing associations of benefit, but subsequent randomized clinical trials have failed to prove effectiveness in reducing mortality (i.e. remdesivir, hydroxychloroquine, lopinavir/ritonavir, colchicine, convalescent plasma and single monoclonal antibodies).

Now we have Ivermectin. Ivermectin is an anti-parasitic medication that has been the focus of speculation as an anti-viral and anti-inflammatory medication against SARS-CoV-2 and COVID-19.


We could go through all the issues of every single trial on Ivermectin, but I think some important messages from the trials would be more prudent. The story starts with in vitro evidence showing that Ivermectin could potentially reduce viral replication and therefore help kill SARS-CoV-2.  You know what else kills anything living in a Petri dish?  Bleach!  What works in vitro, does not always pan out in vivo.

The Cochrane review (published July 2021) stated in their conclusion, “We found no evidence to support the use of Ivermectin for treating or preventing COVID-19 infection, but the evidence base is limited.”

All the trials thus far discuss the efficacy of Ivermectin in the treatment of COVID-19 at various time points in illness, but very little is mentioned about safety.  Due to its massive global use in low- and middle-income countries, the knowledge base establishing a high margin of safety and low rate of adverse effects is nearly unparalleled.  However, the doses used are prophylactic doses. A single dose of subtherapeutic Ivermectin most likely dose not exert a beneficial effect nor cause any severe adverse effects.  The doses needed to reach IC50 (Concentration resulting in 50% inhibition) at a pulmonary level are much higher than what a single dose would achieve.

It would take doses 10 times higher than the approved single dose amount to achieve any type of potential therapeutic effect.  What happens when you take supratherapeutic doses of Ivermectin?  You get an increase in toxicity as is evidenced by the increase in calls seen by the National Poison Data System (NPDS).


Finally, disinformation has been a real issue throughout the pandemic. We are seeing more and more trials on Ivermectin retracted due to falsified data.  Just to name a few here:

  1. Kory P et al. clinical and Scientific Rationale for the “MATH+” Hospital Treatment Protocol for COVID-19. J Intensive Care Med 2021. PMID: 33317385 [Link is HERE]
  2. Elgazzar A et al. Efficacy and Safety of Ivermectin for Treatment and Prophylaxis of COVID-19 Pandemic. Research Square 2020. [Link is HERE]
  3. Samaha AA et al. Effects of a Single Dose of Ivermectin on Viral and clinical Outcomes in Asymptomatic SARS-CoV-2 Infected Subjects: A Pilot Clinical Trial in Lebanon. Viruses 2021. PMID: 34073401 [Link is HERE]

The definition of insanity is doing the same thing over and over again and expecting different results.  We have seen the adoption of therapeutics too early during this pandemic, including Ivermectin, with many of them not panning out with subsequent high quality randomized clinical trials.

Long Live Horse Paste!

With masks, Salim suggested that we don’t allow “perfect to be the enemy of good.” If we try to apply that same reasoning to Ivermectin use, the narrative shifts. Ivermectin advocates are uniformly ostracized as abject right-wing idiots who enjoy eating horse dewormer and chugging swimming pool cleaner. Those comparisons are about as dumb as saying that people who drink water are ingesting a nuclear reactor coolant, but hey – I already warned you about the evils of social media.

So deep is anti-Ivermectin sentiment that I was personally chastised by a moderator on a national medical message board for being too “political” when I dared to just mention the “I-word.”

Ivermectin is extremely effective as an anti-parasitic and its discovery resulted in the award of a Nobel Prize. Since then, multiple studies show that ivermectin is also highly effective in stopping viral replication of SARS-CoV-2. See, e.g., This study showed that Ivermectin had the highest binding affinity to SARS-CoV-2 proteins of any drug studied. Pay no attention to these studies, though. Remember that Ivermectin is horse paste and it’s too political.

Salim mentions in vitro versus in vivo results. Many studies outside petri dishes show the dramatic effect Ivermectin has on improving COVID outcomes. Scientists just need to read them.

One study by Tanikoa showed that morbidity and mortality from COVID-19 was 700% TO 800% higher in African countries where onchoceriasis was non-endemic compared to countries where it was endemic. The biggest difference between the two groups? Countries with lower mortality rates were using large amounts of Ivermectin to treat onchoceriasis.

In Peru, excess deaths during the COVID-19 pandemic decreased by 93% upon widespread distribution of Ivermectin in 14 states. Lima restricted Ivermectin use and its death rate during that same time frame decreased by only 25%.

Deaths in the 14 low excess death states increased by 1,300% within 30 days after the newly elected Peruvian president imposed a national restriction on Ivermectin use.

An observational study in India showed that counties using ivermectin had COVID-19 rates drop by up to 97% while counties that did not use Ivermectin had 700+% increases in COVID-19 cases. This study was “debunked” by the web site … wait for it … PolitiFact.

The Indian Bar Association filed a notice of contempt against WHO physicians that suggested Ivermectin was ineffective as a COVID treatment. Those statements reportedly undermined an India Supreme Court opinion stating the opposite. The WHO physician’s assertions could reportedly constitute a criminal act with a maximum punishment of death under Indian law. Side note – attention ABEM and FSMB: Still think punishing COVID “misinformation” is a good idea?

If you want to learn about multiple other Ivermectin studies showing a combined 87% improvement in COVID outcomes with early Ivermectin treatment, go to However, you should probably just ignore all that research, too. It’s horse dewormer, people.

Why aren’t we performing further investigations on Ivermectin use in the US? Who knows? Luckily, we almost have a new miracle drug called molnupiravir that costs $700 per treatment course, has worse treatment outcomes than Ivermectin and can reportedly cause mutations of genetic material in mammalian cells, predisposing to cancer and birth defects.

I’m sure the medical establishment will ignore these issues as well. The federal government already purchased more than $1 billion worth of molnpiravir and has options to purchase an additional $2 billion more.

I’m glad Salim mentioned remdesivir because continued use of that medication helps prove that some prescribers care more about social media reports than they care about science. Early in the pandemic, the WHO concluded that remdesivir was ineffective as a treatment against COVID.

Many doctors ignored this study and continued prescribing remdesivir. Strange how there weren’t news articles calling remdesivir “Ebola treatment” and how scientists weren’t banned from social media for merely mentioning the drug’s name. How many people suffered liver or kidney damage and how many billions of dollars were wasted when medical providers prescribed a medication known to be ineffective?

It is appalling when, in treating a virus that the entire world has studied for nearly two years, the standard of care for early treatment amounts to “go home and come back if you get worse.” I predict that when patients suffer an adverse COVID outcome, “loss of chance” lawsuits will increasingly be filed against providers who refuse to prescribe potentially life-saving medications and against pharmacists who refuse to dispense those medications.

Studies show that Ivermectin is an effective treatment for COVID-19. If you’re still questioning whether to prescribe a “horse dewormer” as a potential COVID treatment, try to find a news report about a horse dying from COVID.


EDITOR-IN-CHIEF Dr. Rezaie is founder and editor of R.E.B.E.L EM.

SENIOR EDITOR DR. SULLIVAN, an emergency physician and clinical assistant professor at Midwestern University in Illinois, is EPM’s resident legal expert. As a health law attorney, Dr. Sullivan represents medical providers and has published many articles on legal issues in medicine. He is a past president of the Illinois College of Emergency Physicians and a past chair and current member of the American College of Emergency Physicians’ Medical Legal Committee. He can be reached at his legal web site


  1. True science DEMANDS that all researchers keep a healthy skepticism regarding ‘facts’ and ‘findings’. Questioning these are the hallmark of scientific research. As I have read elsewhere, failure to question findings leads to blindly ‘following the leader’, which is nothing more than propaganda! How can physicians trained in the scientific method totally ignore reports of very beneficial results of ivermectin and 6-hydroxychloroquine used early in the COVID infection? I don’t understand it. There should be a rush to begin clinical trials (but I think that there are many who do not want these done. Now look at the article on a vasculitis on a UC patient who received the COVID vaccine. This is definitely harmful. So where did ‘primum non nocere’ come into this?
    The politicization of medicine should be avoided, not embraced, at all costs.


    Milton L Pozo, MD., FACP.

    More than a year ago, the CDC redefined successful vaccination as prevention of hospitalization and death. Unfortunately, the common popular understanding and the now explicit published results support the definition found in the Merriam-Webster dictionary: any preparation used to render an organism immune to some disease, by inducing or increasing the natural immunity mechanisms.
    The narrative shifted to observation [go home. Quarantine if you have been in close contact (within 6 feet of someone for a cumulative total of 15 minutes or more over a 24-hour period) with someone who has COVID-19 unless you have been fully vaccinated. People who are fully vaccinated do NOT need to quarantine after contact with someone who had COVID-19 unless they have symptoms. However, fully vaccinated people should get tested 5-7 days after their exposure, even if they don’t have symptoms, and wear a mask indoors in public for 14 days following exposure or until their test result is negative]. (COVID-19 Quarantine and Isolation | CDC)
    Unfortunately, that notion of vaccination and distorted prevention did not stand the scrutiny of Nature, as all statistics of new cases, hospitalizations and death indicate.
    Several sources have presented the constitutive elements of a true prophylaxis protocol. However, the disparity of dosing has not only caused confusion but has lessened its efficiency.
    The constitutive elements of this Prophylaxis Protocol are Zinc (Gluconate, Citrate or Picolinate), Vitamin D3, Vitamin C, and Quercetin. True, other micronutrients can be added but the effectiveness of this Protocol is 99% in preventing the infection and aids in a faster recovery of those infected and sick. (Private data on 500 cases)
    I will be happy to present this Protocol, and the Methodology to conduct an Observational Study.

  3. Daniel Levy, MD, FACEP on

    Perhaps Dr. Rezaie is unaware of what I believe is a smoking gun in big medicine/pharma’s financially-motivated battle against ivermectin, directed incongruously by Dr. Andrew Hill, once a strong supporter of the medication. By accepting a massive “donation” to his institution and then “changing his mind” about an inexpensive, safe, widely available and internationally effective treatment, he and others in government could be responsible for hundreds of thousands of avoidable deaths by steering the American medical community away from effective early treatment:

    “While the original Hill manuscript was obviously favorable to ivermectin, that changed when the paper was modified during the final stages of the meta-analysis paper review process by influencers other than Hill. While Hill acknowledged in an email transaction to TrialSite several months ago that he was fully fine with the changes, accepting the modifications as part of the process, some critics propose that Hill was part of what is essentially an unethical, highly biased reactive process designed to delay any positive rulings associated with the generic anti-parasitic drug.

    Adding fuel to the conspiratorial fire was the report that just days prior to publication of his meta-analysis, his sponsor, Unitaid, awarded $40 million to the University of Liverpool, according to the World Tribune account. TrialSite confirmed this funding via the Unitaid website.”

  4. Howard W. Randall on

    “If you’re still questioning whether to prescribe a ‘horse dewormer’ as a potential COVID treatment, try to find a news report about a horse dying from COVID.”

    Try to find a human being who kicked the bucket due to laminitis.

    “A horse is a horse of course of course
    “And no one can talk to a horse of course.
    “That is of course unless the horse
    “Is the famous Mister Ed!”

  5. I’ve been informed that people on several social media outlets had questioned why EPM would even consider publishing this article. These social media posts reportedly contained no citations to studies showing ineffectiveness of ivermectin. These social media posts also reportedly had no arguments against the validity of the studies I cited. The entirety of the argument against publishing this piece and others before it about masks ( and (ironically) social media ( was that those articles were too “political.”
    If true, how disappointing that for some colleagues, science has been reduced to baseless demands for censorship rather than a desire for scholarly debate. And we wonder why public trust in the medical profession is waning.
    I’m offering a standing challenge to debate any physician in any forum (including EP Monthly) regarding science behind the use of ivermectin for treatment of COVID. If you believe that the science is so settled against ivermectin use that we shouldn’t even be discussing it as a treatment option, bring your overwhelming evidence and let’s put the issue to rest.

  6. David Bardsley, MD on

    Dr Sullivan,
    Regarding the study by Tanikoa, who came up with the “biggest difference between the two groups”? I think that it would also be important to know how he(they, you) came up with that conclusion. I’m a seeker of truth and scientific fact, so I will be working through your piece and coming back with more questions soon.

  7. Dr Sullivan,
    Ivermectin debate aside, I am dumbfounded by your comment “It is appalling when, in treating a virus that the entire world has studied for nearly two years, the standard of care for early treatment amounts to “go home and come back if you get worse.” We have studied many, many other diseases for much, much longer and have not done much better…influenza for one. We are not as good at this medicine thing as we think we are.

  8. William Doyle,MD on

    Thank you to epmonthly for the courage to print the viewpoint of Dr. Sullivan while in our currently politically charged atmosphere intended to discourage such thinking. I have been referring colleagues to review with an open mind the information available at for some time and am generally countered with a smug dismissal along with an atmosphere expressing a combination of both bafflement and pity that I could be so easily snookered by such misinformation. I would have a better reception had I referred them to a porn site.
    In a hopefully sane future when the truth of all the current confusions and agendas has been unwound and it appears that those with the open minds where those willing to seriously consider all treatment options in order to promote the welfare of their patients and their communities, in the here and now , while patients are dying, without having the recourse to wait for the fantasy double blind study that will take years and magically answer all questions, will any apologies be forthcoming ? Will the power of ABEM to unilaterally decide the fate of our careers be questioned?
    I’m not holding my breath.

  9. Thanks to everyone for the continued feedback.
    Dr. Bardsley, I am the one who came up with the “biggest difference between the two groups” statement. Unfortunately a pro/con article limited to +/- 700 words does not allow the opportunity to describe multiple studies in detail while still trying to bring out salient points of all the studies. Would be happy to discuss study findings in depth with you either online or via e-mail. Feel free to write me.
    Dr. Schare, point taken and I agree with you. In fact, when considering almost all viral illnesses, we do just that – tell patients to go home and come back if they get worse. Poor wording on my part. The idea I wanted to convey (within the word limits imposed) is that multiple treatments have been studied and showed beneficial effects in the outcome of patients with COVID infections. Those studies aren’t limited to ivermectin. Despite knowledge of those potentially beneficial treatments, the current standard is to send patients home with none of those treatments. Then we wait for patients to become sicker and prescribe them medications such as remdesivir that was shown to have multiple serious side effects and which the World Health Organization has deemed as having no benefits in outcomes with COVID patients. Physicians frequently prescribe antibiotics for “sinus infections” and coughs when those antibiotics are unlikely to have any clinical benefit. For some reason, there is an opposite mindset when treating COVID – prescribe NOTHING even when multiple studies and outcomes in other countries demonstrate the potential for a significant clinical benefit.
    Dr. Doyle, I laughed at your “porn site” comment. I agree with you. I think in 10-15 years we’ll look back at this era in medicine with disdain and wonder why so many medical professionals simply refused to acknowledge science and the scientific method. I predict a groundswell of COVID litigation in the future. It will be difficult for physicians, hospitals, and medical groups to justify their decisions to ignore large amounts of medical literature.

    • Jack D England DO on

      Thanks to Dr. Sullivan and Dr. Rezale for doing the article on ivermectin. Iwas also surprised that Dr. Sullivan answered his phone when I called. I’m a full clinical professor at 3 Osteopathic Medical Schools and an associate professor at Colorado University Medical School in emergency medicine and family practice but unlike most professors I only practiced and am not published. I’ve preceptored medical students and residents for over 40 years. Let’s get to it. I believe that we have the total package to treat covid and since this aricle is on ivermectin my opinion is that this is saving thousands or hundreds of thousands of lives in multiple countries around the world. I’ts almost magical because it is cheap, saves lives and has few side effects. Dr. Harvy Risch from Yale was asked how many lives in the USA would have been saved with early treatment with ivermectin and the other things at our disposal. He said if there have been 700,000 deaths due to covid 80-85% would not have died. The FLCCC has looked at trials all over the world and the results of these trials and observations look great for ivermectin and hcq. Utter Pradesh in India almost wiped out covid in a few weeks with its putting the millions of people on ivermectin. Dr Razaie is totally wrong on the data with Dr. Kory. He figured out that the usual treatment was so delayed that by the time patients were sent to them over 80% that went on respirators died. Most of the doctors talking out on ivermectin have lost their positions and that is a shame. Many of the early cheap things work together. So the conventional doctors basically have minimal treatment that works and we have more deaths after we have the vaccines. We need to wake up.

  10. Jack D England DO on

    This idea that ivermectin hcq are bad just amazes me. There so many excellent studies on both. The main problem is that the hysteria that has gone on defies common sense. There have been minimal options when one goes to an urgent care or ER. Patients get virtually nothing to help them. Let’s not use common sense. Look at ivermectin, it does everything I look for. It is inexpensive, has minimal side effects and has saved more lives than anything I can think of. One example is the state of Utter Pradesh in India. Last spring, they were averaging 35,000 cases a day and 350 deaths. On August 5th they had 27 cases and 2 deaths after putting the whole state on ivermectin that were sick and others for prevention. Utter Pradesh is smaller than Colorado but has 240,000,000 people and a low vaccination rate. Several states followed this protocol and had great results, but the ones that followed more practice in the USA had lousy results like we get. We are continuing to have bad results and more deaths in 2021 with the vaccine than the year before without it. I am a clinical professor at 3 medical schools in EM family practice. So early treatment with these drugs, Vit D, C zinc, quercetin and many others offer a lot, conventional medicine not so much.

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