WASHINGTON— The scientific journal Regulatory Toxicology and Pharmacology has issued a rare retraction of one of the most cited studies on the safety of the pesticide glyphosate, the main ingredient in the weedkiller Roundup.

The study, which found that glyphosate poses no cancer or other health risks to people, was retracted because it relied exclusively on unpublished Monsanto studies. The study failed to review any research that was not conducted by Monsanto, the maker of glyphosate, now owned by Bayer. The journal also found that the paper may have been ghostwritten by Monsanto employees and that financial compensation from Monsanto was not disclosed.

The article has been cited extensively by regulatory agencies around the world, including the U.S. Environmental Protection Agency, as evidence that glyphosate poses no cancer risk to humans. The paper is in the top 0.1% of cited articles on glyphosate in the scientific literature, meaning it is more highly cited than 99.9% of articles written on the chemical.

“The pesticide industry’s decades of efforts to hijack the science and manipulate it to boost its profits is finally being exposed,” said Nathan Donley, environmental health science director at the Center for Biological Diversity. “The EPA must take immediate action to reassess its finding that glyphosate is not a carcinogen. That means rather than relying on Monsanto’s confidential research of its own product, the agency needs to follow the gold standard of independent science established by the World Health Organization in its finding that glyphosate probably causes cancer.”

The retraction of the most-cited paper on glyphosate safety comes the same week that the Trump administration submitted a brief enthusiastically supporting Bayer in its U.S. Supreme Court bid to throw out thousands of lawsuits claiming the company is liable for failing to warn the public of cancer risks of glyphosate.

The successful class action litigation that Bayer and the U.S. government are seeking to overturn directly led to the release of emails that were used as primary evidence for the study’s retraction.

The Trump administration’s support of the pesticide industry in court filings directly contradicts 2022 court filings by the Biden administration asking the high court not to hear a similar case Bayer brought. The Supreme Court declined to hear the case in 2022 but is now once again considering Bayer’s request.

“Now that much of the research finding glyphosate poses no cancer risk has been undermined, it is especially outrageous that the Trump administration is seeking to bolster Bayer’s case,” said Donley. “Trump promised the American public his administration would protect Americans from dangerous chemicals and pesticides, but now it’s throwing its full weight behind Bayer’s desire to deny cancer victims their day in court. This is a massive betrayal of the public and an unabashed prioritization of corporate wealth over public health, plain and simple.”

This week’s paper retraction comes roughly seven years after scientists at the Center for Biological Diversity, Center for Food Safety, Pesticide Action Network, and Center for Environmental Health requested a similar retraction of a 2016 supplemental issue titled “An Independent Review of the Carcinogenic Potential of Glyphosate” because the review article was covertly edited and funded by Monsanto.

That request, made to the journal Critical Reviews in Toxicology, resulted in an “Expression of Concern” because the authors failed to include an accurate disclosure of the pesticide-maker’s involvement. The articles at issue were all highly critical of the 2015 finding by the World Health Organization’s International Agency for Research on Cancer that glyphosate is a probable human carcinogen.

Despite the misconduct that Taylor and Francis, the publisher of Critical Reviews in Toxicology, acknowledged in the Expression of Concern, the publisher refused to issue a retraction for the papers, in contradiction to its own corrections policy, and has allowed the title of the supplemental issue to retain the phrase “an independent review.”

This is despite the fact that there is written evidence that at least one Monsanto employee extensively edited the manuscript and was adamant about retaining inflammatory language critical of the IARC cancer finding — against some of the authors’ wishes. The disclosure falsely stated that no Monsanto employee reviewed the manuscript.