A pivotal scientific paper, published in the year 2000 and long cited by regulators worldwide as proof of the safety of glyphosate herbicides, has been formally retracted by the journal that published it. The retraction cites 'serious ethical concerns' about the authors' independence and the academic integrity of the research.
The Ghostwriting Scandal Uncovered
The paper, titled 'Safety Evaluation and Risk Assessment of the Herbicide Roundup and Its Active Ingredient, Glyphosate, for Humans', concluded that Monsanto's glyphosate-based weed killers, including Roundup, posed no cancer, reproductive, or developmental health risks to humans. Its authors were listed as three external scientists: Gary Williams, Robert Kroes, and Ian Munro.
However, internal Monsanto documents revealed in US litigation showed the company's deep involvement. Emails disclosed a corporate strategy called 'Freedom to Operate' (FTO) and celebrated the publication as a major victory. One email from May 2000 by Monsanto official Lisa Drake praised the 'perseverance, hard work and dedication' of seven named Monsanto employees for their three years of work on the paper's data, writing, and relationship-building with the authors.
In a 2015 email, Monsanto scientist William Heydens explicitly suggested ghostwriting a new paper by paying outside scientists to 'edit & sign their names', noting 'that is how we handled Williams Kroes and Munro 2000.'
Regulatory Reliance and Legal Fallout
For decades, this study was referenced by global regulators, including the US Environmental Protection Agency (EPA), as key evidence in safety assessments. Its retraction now casts a long shadow over that regulatory history.
The journal's editor-in-chief, Martin van den Berg, stated the retraction was due to concerns over misrepresentation of contributions by the authors and sponsor, and potential conflicts of interest. He noted the paper's conclusions on carcinogenicity relied solely on unpublished Monsanto studies, ignoring other external, published research.
Bayer, which bought Monsanto in 2018, stated that Monsanto's involvement was acknowledged in the paper's credits and that most studies on glyphosate had no company input. The EPA confirmed it was aware of the retraction but asserted it 'has never relied on this specific article' for its regulatory conclusions, pointing to its review of over 6,000 studies.
A Long-Awaited Reckoning for Scientific Integrity
Brent Wisner, a lead lawyer in the Roundup litigation, called the retraction 'a long time coming.' He described the study as the 'quintessential example' of how companies can undermine peer-review through ghostwriting and cherry-picking data. 'This garbage ghostwritten study finally got the fate it deserved,' Wisner said, expressing hope journals would now be more vigilant.
The retraction news emerged the same week the Trump administration urged the US Supreme Court to back Bayer's attempt to limit thousands of lawsuits alleging Roundup causes cancers like non-Hodgkin lymphoma. The plaintiffs argue they were not warned of the risks.
Of the original paper's authors, Robert Kroes and Ian Munro are deceased. Gary Williams could not be reached for comment; a 2017 investigation by his former employer, New York Medical School, found no evidence he violated rules against authoring a ghostwritten paper.
