A French scientist whose Covid-era research was publicly promoted by Donald Trump and Dr Mehmet Oz is facing renewed scrutiny after a new analysis identified hundreds of his institute’s papers as carrying “substantial” ethical and legal red flags.
The review, conducted by an international group of researchers, found problems in 853 articles published by the Institut Hospitalo-Universitaire Méditerranée Infection, known as IHU. That total is hundreds higher than the number previously identified in earlier inquiries into the major research hospital’s output. Didier Raoult, the institute’s founder, was named as a co-author on 758 of those papers, according to one researcher involved in the analysis.
Raoult became a worldwide figure in March 2020, as Covid-19 was spreading rapidly and deaths were mounting across the globe. He and several colleagues released a study claiming that hydroxychloroquine — a drug long used to treat malaria and some autoimmune diseases — could effectively treat Covid-19, particularly when paired with the antibiotic azithromycin.
Trump quickly seized on the research, describing hydroxychloroquine as a potential “gamechanger”. Many scientists, however, urged caution and questioned the quality of the evidence, including Dr Anthony Fauci, who was then serving as a leading adviser in the Trump administration’s pandemic response.
Despite those warnings, Oz — now the head of the US Centers for Medicare and Medicaid Services, which oversees roughly $1.6tn in spending — also used the term “gamechanger” when discussing Raoult’s findings. The attention extended well beyond the United States: French president Emmanuel Macron visited the institute and met with Raoult, while Robert F Kennedy Jr later praised the research as “powerful” and dedicated part of an anti-Fauci book to the French microbiologist.
Hydroxychloroquine has not been proven effective as a Covid-19 treatment, and the high-profile paper was eventually retracted in 2025 over ethical and scientific concerns. By then, it had become one of the pandemic’s most widely known studies, cited thousands of times and repeatedly invoked in public debate.
The latest findings add to broader questions about the scientific judgment of current health officials in the Trump administration, who have pledged to restore what they describe as “gold-standard science” to federal policymaking. The scrutiny comes as a Republican-led US Senate committee recently voted to hold Fauci in contempt after he invoked the fifth amendment during a hearing on the origins of Covid-19.
“If Oz had reviewed/read the study correctly he would have found many of the problems” that critics later identified, said Lonni Besançon, an assistant professor in data visualization at Linköping University in Sweden. Besançon was part of the international team behind the new analysis, which was published this month in the journal Research Integrity and Peer Review.
Besançon said the now-retracted article was used to claim there was a cure for Covid, led to shortages of hydroxychloroquine and drove scientists to pour their attention into researching that drug rather than other promising leads. It also fueled conspiracy theories from people who argued the article was being attacked “because if there was a cure for Covid then they couldn’t sell their vaccines”, he said.
“A lot of time was wasted,” Besançon said. “It’s been a massively influential paper, and it’s also been used to push for an antivax agenda.”
Fauci, who was a leading member of the White House coronavirus taskforce, was asked at a news conference with Trump on 20 March 2020 whether there was evidence hydroxychloroquine could be used to combat Covid-19. Fauci, standing with the president, replied, “The answer is no,” called such research “anecdotal evidence” and noted it was not done in a controlled clinical trial. He called for rigorous scientific research to show whether it would be both safe and effective.
But the next day, Trump cited Raoult’s research in a tweet, saying hydroxychloroquine and azithromycin “have a real chance to be one of the biggest game changers in the history of medicine” and saying he hoped they would be put in use immediately.
Two days later, Oz, then a TV personality and physician, appeared on Fox & Friends, where he said he was “flabbergasted” by Raoult’s research and urged the US government to procure the drug.
“I read the study. I was stunned. Literally, a jaw dropped. I didn’t know it was possible,” Oz said.
While Oz noted it had not been a randomized trial and said he was launching his own such trial to replicate Raoult’s findings, he also called the French work a “gamechanger”.
“The data is so strong, I completely understand why America wants to start taking these pills,” Oz said, before adding that more data was needed.
Publicly, Oz interviewed Raoult multiple times in March and April for his TV show.
Behind the scenes, Oz was emailing Trump administration officials to highlight the research, according to emails later obtained by a US House select committee on the coronavirus crisis. In them, Oz vouched for the quality of Raoult’s research.
“You should know that the French researcher confirmed clinical benefits but needs more data so will not release report for another 10 days. These findings offer hope to our people,” Oz wrote on 22 March. He called it a “potential pandemic solution” in an email to Trump’s son-in-law Jared Kushner.
Six days later, he wrote that Raoult had sent him updated research and that “the treatment appears safe and results are better than expected”.
Trump’s current health secretary, Robert F Kennedy Jr, then leading the anti-vaccine activist group Children’s Health Defense, named Raoult among the “heroic” scientists to whom he dedicated his 2021 book, The Real Anthony Fauci. Kennedy’s book attacked Fauci for his stance toward hydroxychloroquine.
The Department of Health and Human Services and the Centers for Medicare and Medicaid Services did not return requests for comment about Kennedy’s and Oz’s promotion of Raoult’s work.
Widespread ethical problems
The team of researchers has been digging into the IHU’s work for years. They initially looked at 2,674 papers published by the institute between 1994 and 2024 and discovered various ethical concerns in 853 of them.
For example, the team noted that French law requires certain steps be taken when using human subjects in biomedical research in order to protect people from harm. The team estimates that at least 78 articles describe biomedical research “that appears not to comply with the applicable French law”, they wrote.
The team also found 343 articles in which no ethics approvals were ever recorded, dozens of approvals that appear to have been obtained retrospectively after the study began and repeated reuse of ethics approvals for different studies, among other issues.
They noted that while issues such as fraud and plagiarism often get more attention when it comes to research misconduct, ethical problems can undermine public trust in research and in the scientific process.
The findings have in the past few years led to 64 articles being retracted and 270 being tagged with an “expression of concern”, which can indicate that major and credible concerns have been raised about the article, the team wrote.
They called for additional review of the institute’s work “to ensure that the scientific record is corrected where appropriate”. It was critical of the institute as well as of Aix-Marseille University, which they said was largely responsible for overseeing the work there.
“These findings raise broader questions regarding the university’s governance and oversight mechanisms,” they wrote.
Besançon said millions of euros in research funds were “thrown out the window” due to the poor research practices at the IHU, and many students were improperly trained in scientific practices.
“For me, this is what’s important,” he said in an interview. “To make sure we can push for good, scrutinizable and responsible science.”
The university said in a statement that it “conscientiously and responsibly” took “all measures within its remit” from when it was first alerted to problems in 2020. It said it did its own investigation and transferred its findings to relevant authorities, then fully cooperated with the investigations. It said it also “engaged with scientific publishers” and has “continuously strengthened its prevention, support and oversight mechanisms”.
“Research ethics and research integrity are fundamental pillars of Aix Marseille University’s research policy and are at the heart of its commitment to responsible, rigorous and high-quality research,” it said.
Raoult retired in 2021. Though he responded to emails sent to him by the Guardian, he did not address questions about his research and the team’s analysis. In the past, he has stood by his research and criticized decisions to retract his studies. He told Science magazine in 2024 that he followed ethical regulations.
The Guardian also sought comment from the IHU.
