Fact Check-Merck’s experimental COVID-19 antiviral drug is not ‘repackaged ivermectin’

Some social media users have been saying that Merck’s experimental COVID-19 antiviral product molnupiravir is a rebranded version of the anti-parasitic Ivermectin. Two disease experts have told Reuters that this is not the case and that the chemical make-up of the two drugs is different.

The posts

One tweet (here) reads, “Ivermectin is a safe cure that was removed from CDC treatment protocol. Merck refurbishes it and *poof, it’s a miracle pill. Further proof that Big Pharma is in the business of creating customers.”

Similar posts on Facebook are visible here and here .

One reads, in part, “The pharmaceutical giant Merck just “developed” a pill that does the same thing as Ivermectin.”

The professors

Dr. Stephen Griffin, virologist and associate professor at the University of Leeds (here), told Reuters that molnupiravir is not repackaged ivermectin.

The two drugs have “dissimilar chemistry,” he said. “There is no way that Merck is doing this,” he said.

“Molnupiravir is a derivative of a nucleotide that, predictably, interferes with the RNA replication of the virus. While Ivermectin does also have a defined mechanism of action, BUT it’s against ion channels found in parasites,” Griffin said.

Information profiles are viewable on for molnupiravir (here) and ivermectin (

Paul Auwaerter, the Clinical Director of the Division of Infectious Diseases (here) at Johns Hopkins Medicine told Reuters via email that the only similarity the two drugs have is that they “have been brought to the FDA for market approval by the Merck Company.”

The professor pointed to structural differences between the two drugs, which can be explored in papers here and here and drug class differences. “Ivermectin is classified as a macrocyclic lactone. It is derived from Streptomyces avermitilis which is a bacterium." Molnupiravir, rather, is classified as a nucleoside analog (like some HIV medications) and works as an antiviral, he said.


According to August 26, 2021, guidance from The Centers for Disease Control and Prevention (CDC), visible here , ivermectin is a U.S. Food and Drug Administration (FDA) approved prescription medication “used to treat certain infections caused by internal and external parasites.” The drug is not currently approved for the treatment of COVID-19. The CDC document also notes increased “ivermectin dispensing by retail pharmacies has increased, as has use of veterinary formulations available over the counter but not intended for human use.”

The FDA continues to caution the public about the potential risks of ivermectin use for prevention or treatment of COVID-19 as of this article’s publication (here).

Previous Reuters reporting on the dangers of using ivermectin as a treatment for COVID-19 is visible here and here .

Clinical trials studying the effectiveness of the anti-parasitic drug for COVID-19 can be seen here and here .

Merck makes Ivermectin, but the manufacturer has said it does not support its use as a treatment for COVID-19; a February 11 company statement is visible here .

Merck did not immediately respond to a Reuters request for comment.


In an October 1 press release visible , Merk said its new investigational antiviral medication molnupiravir reduced the risk of hospitalization or death of those infected with COVID-19 by approximately 50% compared to a placebo.

The company is seeking Emergency Use Authorization (EUA) from the U.S. FDA for the pill (more here and here ).

Debunks on claims about molnupiravir being repackaged ivermectin have also been taken on by Snopes here and Full Fact, here .


False. Claims that Merck’s antiviral molnupiravir is repackaged ivermectin are false. According to two virologists, the two drugs are chemically different.

This article was produced by the Reuters Fact Check team. Read more about our fact-checking work here .