A widely cited scientific article used for decades to support the safety of glyphosate, the world's most used herbicide and the active ingredient in Roundup, has been retracted by the journal Regulatory Toxicology and Pharmacology. The decision follows findings of undisclosed corporate involvement by Monsanto, the original developer of the product now owned by Bayer.

The 25-year-old paper, authored in part by Gary Williams and others, had long been considered a cornerstone in glyphosate's regulatory defense, particularly regarding its alleged non-carcinogenicity. But Co-Editor Martin van den Berg said concerns about ghostwriting, potential financial compensation, and lack of transparency have compromised the article's credibility.

Van den Berg explained that the paper's conclusion - that Roundup does not pose a health risk to humans - rested heavily on unpublished studies by Monsanto and failed to include other relevant chronic toxicity data available at the time. "The failure to disclose Monsanto's direct involvement in drafting the manuscript undermines the academic independence of the findings," he stated.

Even more troubling, litigation against Monsanto revealed correspondence suggesting the authors may have received undisclosed compensation, raising serious ethical concerns about the integrity of the research. "This omission suggests that the authors may have misrepresented their unique roles and the collaborative nature of the work presented," van den Berg wrote.

Although Bayer insists Monsanto's role "did not rise to the level of authorship" and was appropriately disclosed in acknowledgments, the journal's retraction cites a lack of clarity and potential misrepresentation. According to Bayer's statement, the paper's influence has waned over time and was not relied upon in recent EU assessments. They emphasized that glyphosate has been studied extensively and regulatory agencies globally - including EFSA and EPA - still consider it safe when used as directed.

Still, the fallout may be significant. The paper had shaped regulatory, legal, and public understanding for over two decades and was cited hundreds of times. A 2025 analysis by Harvard historian Naomi Oreskes and researcher Alexander Kaurov underscored its profound impact on scientific discourse and policy, calling the retraction a watershed moment.

The EPA, which concluded in 2020 that glyphosate was unlikely to cause cancer, is currently re-evaluating its human health assessment following a court order that cited flaws in its review.

The issue of industry influence in scientific research is not new, but this case is likely to reignite debate over how regulatory decisions are informed. With over 61,000 lawsuits still pending against Bayer and more than $10 billion already paid in settlements linked to Roundup exposure, the credibility of foundational science behind glyphosate is under scrutiny like never before.

The lone surviving author, Gary Williams, has not responded to inquiries. For now, the glyphosate safety narrative faces renewed pressure - and policymakers, farmers, and consumers may need to re-evaluate long-held assumptions about one of agriculture's most ubiquitous chemicals.