Ivermectin, on the record: a Nobel-winning drug caught in a culture war

Picture the person at the center of this: maybe a farmer in West Africa whose eyesight a single yearly pill has saved, or a frightened parent in 2021 scrolling past a federal agency telling them they are "not a horse." Same molecule. Two completely different stories. NU separates what the record actually supports from what the fight made people believe. Records over spin.

This is not medical advice. Talk to a licensed clinician about any treatment decision.

1. The part people feel

In the summer of 2021, ivermectin stopped being a pharmacology question and became a tribe test. One side heard "miracle cure the establishment is hiding." The other heard "horse dewormer for conspiracy theorists." Both heard slogans. Almost nobody got handed the boring middle — which is where the truth usually lives.

So here is the boring, verifiable middle.

2. The legitimate drug (this part is not disputed)

Ivermectin is a real, important, award-winning medicine. It was developed from avermectins, compounds isolated from the soil bacterium Streptomyces avermitilis. Satoshi Ōmura and William C. Campbell shared the 2015 Nobel Prize in Physiology or Medicine for that discovery work — half the prize, alongside Tu Youyou for artemisinin, the Nobel committee states 【1】.

Its legitimate, approved uses are antiparasitic:

• Onchocerciasis (river blindness) and lymphatic filariasis — treated through mass drug administration. Merck has donated ivermectin (Mectizan) for these diseases since 1987, the company and the WHO state 【2】.
• Strongyloidiasis and other worm infections (oral) 【3】.
• Scabies and head lice (topical, brand Sklice) and rosacea (topical, brand Soolantra), per FDA labeling 【3】.

It sits on the WHO Model List of Essential Medicines 【2】. It is also a workhorse veterinary dewormer — which is the source of the "horse paste" the slogans seized on. The drug is real and valuable. That was never the argument.

3. Where COVID enters

In April 2020, Australian researchers (Caly et al., Antiviral Research) reported that ivermectin inhibited SARS-CoV-2 in a cell culture 【4】. That lab result is real. The crucial caveat — stated by the authors and later by the FDA and pharmacologists — is that the concentrations used far exceeded what is achievable in the human bloodstream at approved doses 【4】【5】. A dish is not a body. That gap is the whole ballgame.

From that single in-vitro finding, a global movement grew, championed by groups like the Front Line COVID-19 Critical Care Alliance (FLCCC) and physician Pierre Kory, who told a Senate panel in December 2020 that the drug was a "wonder drug" against COVID 【6】. That is an accurate quote of an advocate — not an adjudicated finding of efficacy.

4. What the trials actually found

This is the part the slogans skipped. Large randomized controlled trials were run, and the consensus result is no meaningful benefit for COVID-19:

• TOGETHER trial (Brazil, NEJM, 2022, Reis et al.): ivermectin did not significantly reduce hospitalization or ER visits 【7】.
• ACTIV-6 (NIH-funded, JAMA, 2022): no meaningful improvement in time to recovery 【8】.
• PRINCIPLE (Oxford, UK): no clinically useful reduction in recovery time or hospital admission 【9】.

A Cochrane systematic review (2022, Popp et al.) concluded the evidence did not support using ivermectin for treating or preventing COVID-19 outside of well-designed trials 【10】.

The disputed claim vs. the record, side by side:

• Claim (advocates): early meta-analyses showed large mortality reductions.
• Record: several of those early-positive results leaned heavily on studies later retracted or flagged for serious problems — most notably a large Egyptian preprint (Elgazzar) withdrawn over data-integrity concerns, which independent analysts showed had outsized influence on the favorable pooled numbers 【11】. When flawed studies were removed, the apparent benefit largely vanished 【10】【11】.

FDA, EMA, WHO, and NIH all advised against using ivermectin for COVID outside clinical trials 【5】【10】. That is the medical consensus as it stands.

5. The fight the consensus does not erase

NU does not hand either side a free win, so here is the part the "debunkers" gloss over: the FDA's messaging drew real legal heat, and the agency backed down.

The FDA's August 2021 post — "You are not a horse. You are not a cow. Seriously, y'all. Stop it." — is real 【5】. A group of doctors sued, arguing the agency overstepped by appearing to tell people not to take a legally prescribed drug. In 2023 the U.S. Court of Appeals for the Fifth Circuit revived that suit, writing that the FDA is not a doctor and can inform but generally "has authority to inform, announce, and apprise — but not to endorse, denounce, or advise" 【12】. In March 2024, the FDA agreed in a settlement to delete the contested social-media posts 【12】.

Read that precisely: the court did not rule that ivermectin works for COVID. It ruled on the limits of the FDA's authority to editorialize. Both things are true at once — the efficacy claims for COVID are unsupported, and a federal court found the agency's tone crossed a line. That is the kind of two-sided record the broadcast version flattened.

6. NU's bottom line

Ivermectin is a genuine, Nobel-recognized antiparasitic that has protected millions of people from blinding and disfiguring disease — that is settled and undisputed. As a COVID-19 treatment, the best randomized trials and the Cochrane review do not support it, and some early "proof" rested on studies that did not hold up. And the agency that mocked it lost a court fight over how it said so. The molecule is real. The miracle was not. The overreach was. All three can be true.

Note on imagery: the photo is a real image of ivermectin tablets seized by the Austrian Federal Ministry of Finance customs agency (Bundesministerium für Finanzen), via Wikimedia Commons, CC BY 2.0.

Sources 【1】 The Nobel Prize in Physiology or Medicine 2015 — NobelPrize.org. 【2】 Merck Mectizan Donation Program; WHO Model List of Essential Medicines. 【3】 U.S. FDA prescribing information (Stromectol, Sklice, Soolantra); CDC parasitic disease pages. 【4】 Caly L. et al., Antiviral Research, 2020 (in-vitro inhibition). 【5】 U.S. FDA, "Why You Should Not Use Ivermectin to Treat or Prevent COVID-19." 【6】 Senate Homeland Security Committee hearing testimony, Dec. 2020 (P. Kory / FLCCC). 【7】 Reis G. et al., TOGETHER trial, New England Journal of Medicine, 2022. 【8】 Naggie S. et al., ACTIV-6, JAMA, 2022. 【9】 PRINCIPLE trial collaborative group (University of Oxford), 2021–2022. 【10】 Popp M. et al., Cochrane Database of Systematic Reviews, 2022. 【11】 Reporting and analyses on the Elgazzar study withdrawal and its effect on meta-analyses (e.g., Nature, BMJ coverage, 2021). 【12】 Apter v. U.S. Dept. of HHS — U.S. Court of Appeals, Fifth Circuit (2023); FDA settlement, March 2024.