Monsanto Scientists Ghostwrote a 2000 Study Clearing Glyphosate of Cancer Risk, Letting Three Outside Academics Sign Their Names. A Journal Retracted the Paper in December 2025, Twenty-Five Years and 614 Citations Later.

In March 2015, the cancer research arm of the World Health Organization classified glyphosate, the active ingredient in Monsanto's Roundup, as "probably carcinogenic to humans." Monsanto's chief technology officer, Robb Fraley, called the finding an outrage the same week. Internal company documents later showed that Monsanto's public relations campaign to discredit the classification had been assembled before the classification was announced.

Those documents — millions of pages of internal emails, strategy memos, and draft manuscripts turned over during a decade of litigation and now known as the Monsanto Papers — became the evidentiary backbone of tens of thousands of lawsuits, a $289 million jury verdict against the company, and, eventually, a $63 billion corporate acquisition that Bayer is still trying to make sense of.

A Classification and a Pre-Written Outcry

On March 20, 2015, the International Agency for Research on Cancer (IARC), the WHO's specialized cancer agency, placed glyphosate in Group 2A — "probably carcinogenic to humans" — citing "limited" evidence in humans and "sufficient" evidence in laboratory animals, alongside a mechanistic link to DNA and chromosomal damage. It was one finding among many the agency reaches every year on substances from red meat to shift work.

Monsanto did not treat it as one finding among many.

• Fraley told reporters the company was "outraged with this assessment," accusing IARC of "cherry picking" data.
• Internal documents released in litigation show Monsanto had lined up public relations and lobbying teams, along with outside scientists, to generate a wave of "outcry" against IARC's conclusion in advance of the announcement.
• A Monsanto scientific affairs executive later disclosed, under oath, a roughly $17 million internal budget for efforts to discredit IARC and defend glyphosate's reputation.

The Paper That Took Twenty-Five Years to Unwind

Among the scientific literature Monsanto leaned on to rebut IARC was a 2000 review in a toxicology journal, authored by academics Gary Williams, Robert Kroes, and Ian C. Munro, concluding glyphosate posed no meaningful risk to human health. It went on to become one of the most cited papers in the glyphosate safety literature — cited more than 600 times over two decades, shaping regulatory reviews and rebuttal after rebuttal to cancer-risk claims.

Court-ordered discovery in the Roundup litigation surfaced the paper's origin story. In an internal email, a Monsanto employee proposed "keeping the cost down" on producing supportive scientific literature by having company staff do the writing while outside scientists "would just edit & sign their names" — and cited the Williams, Kroes and Munro paper as precedent for exactly that arrangement. The paper's acknowledgments thanked Monsanto only for "scientific support."

The journal retracted the paper in December 2025 — twenty-five years after publication, and roughly eight years after the ghostwriting arrangement was first exposed in unsealed litigation documents.

A Stanford Fellow, a Forbes Column, and a Reuters Reporter

The ghostwriting wasn't confined to peer-reviewed journals. In 2015, Henry I. Miller, a fellow at Stanford's Hoover Institution, published a Forbes.com column attacking IARC's glyphosate classification under his own byline. Discovery in the litigation produced the Monsanto-drafted version of the piece: it matched Miller's published column almost word for word. Miller had told Monsanto he needed a "high-quality draft" to work from, citing how busy he was. Forbes subsequently deleted every column Miller had written for the site.

Monsanto's PR effort also extended to shaping how journalists covered the scientist who had chaired IARC's glyphosate review, epidemiologist Aaron Blair. Internal emails show a Monsanto media relations executive coordinating with a public relations firm and supplying talking points to a Reuters reporter for a 2017 story asserting Blair had withheld data that undermined IARC's conclusion. Blair's own deposition testimony — which the resulting article did not quote — did not support that claim.

A Groundskeeper and the First Verdict

Dewayne "Lee" Johnson was a school groundskeeper in Benicia, California, who applied Roundup and a related Monsanto herbicide dozens of times as part of his job, including two incidents in which the chemical soaked his protective clothing and skin. He was diagnosed with non-Hodgkin lymphoma in 2014, then given a terminal prognosis. His case, filed in San Francisco Superior Court, was expedited to trial because he was dying.

• On August 10, 2018, a San Francisco jury found Monsanto liable and that Roundup was a substantial factor in causing Johnson's cancer, awarding $289.25 million — $39.25 million in compensatory damages and $250 million in punitive damages.
• The trial judge reduced the punitive award to $39.25 million that October, cutting the total to $78.5 million; Johnson accepted the reduced amount rather than risk a retrial.
• On appeal, the California Court of Appeal upheld the finding of liability in July 2020 but further reduced the total award to $20.5 million.

It was the first of the Roundup cases to reach a jury. It would not be the last.

The Wave That Followed

Johnson's verdict opened the floodgates. Edwin Hardeman, a California man who used Roundup on his property for decades, won an $80 million verdict in March 2019, later reduced by the trial judge to $25.2 million. Alva and Alberta Pilliod, a married couple who had each developed non-Hodgkin lymphoma after decades of Roundup use, won a $2.055 billion jury verdict two months later — reduced by the trial court to $87 million. Bayer appealed both cases through the California courts and then to the U.S. Supreme Court, which declined to hear either appeal in June 2022, leaving both reduced verdicts intact.

By June 2020, facing what had grown into roughly 125,000 filed and unfiled claims, Bayer agreed to pay up to $10.9 billion to resolve the bulk of the litigation — $8.8 to $9.6 billion for existing claims and $1.25 billion to fund a program addressing future ones. It did not end the litigation. New cases kept being filed, and juries kept returning verdicts far larger than the settlement math assumed: $1.56 billion in Anderson v. Monsanto (2023), $2.25 billion in McKivison v. Monsanto (2024), and $2.065 billion in Barnes v. Monsanto (2025). By 2025, Bayer had paid out more than $10 billion in settlements on top of roughly $14 billion in judgments and continued to face tens of thousands of pending claims.

The Acquisition Bayer Can't Unwind

Bayer completed its $63 billion acquisition of Monsanto in June 2018 — six weeks before the Johnson verdict. The Monsanto name was retired within months; the liabilities were not. Bayer's chief executive since 2023, Bill Anderson, has since said the company is "reaching the end of our road" on Roundup litigation and warned that Bayer may exit the U.S. glyphosate business entirely if it cannot bring the legal exposure under control, telling reporters the company will "either find a solution on these things or we will be exiting the business."

In 2021, Bayer announced it would remove glyphosate from Roundup products sold to U.S. home and garden consumers starting in 2023, replacing it with other active ingredients for that market while continuing to sell glyphosate-based formulas to farmers and professional applicators. Then-CEO Werner Baumann was explicit about the reasoning: the change was "exclusively geared at managing litigation risk and not because of any safety concerns," since roughly 90 percent of the lawsuits came from residential users. In February 2026, Bayer proposed a new $7.25 billion class settlement aimed at resolving current and future non-Hodgkin lymphoma claims; a judge granted preliminary approval the following month, with a final approval hearing set for September 14, 2026.

What the Regulators Say Now

Outside the courtroom, glyphosate remains approved for use nearly everywhere. The U.S. Environmental Protection Agency concluded in 2020 that glyphosate was "not likely to be carcinogenic to humans" — a finding the Ninth Circuit Court of Appeals vacated in June 2022, ruling the conclusion was internally inconsistent with the agency's own supporting analysis and ordering EPA to redo the human-health portion of its review. That review remains pending. In the European Union, the European Chemicals Agency concluded in 2022 that classifying glyphosate as a carcinogen was "not justified," the European Food Safety Authority reached a similar conclusion in 2023, and the European Commission reauthorized glyphosate for another ten years that November.

IARC's 2015 classification — the one Monsanto spent millions trying to discredit before it was even published — has never been withdrawn.

Roundup is still sold in every farm supply store in the United States, its label carries no cancer warning, and glyphosate is approved for use across the European Union through 2033. Somewhere in the discovery record is the email in which a Monsanto scientist thanked a colleague for help keeping a ghostwritten paper's origins quiet — a paper that took twenty-five years, one WHO classification, over a hundred thousand lawsuits, and $14 billion in judgments to finally get retracted.

Filed from public reporting:

• IARC (World Health Organization) — "IARC Monographs Volume 112: Evaluation of Five Organophosphate Insecticides and Herbicides"
• U.S. Right to Know — "How Monsanto Manufactured 'Outrage' at IARC over Cancer Classification"
• Retraction Watch — "Glyphosate safety article retracted eight years after Monsanto ghostwriting revealed in court"
• U.S. Right to Know — "Henry I. Miller" (Forbes ghostwriting profile)
• U.S. Right to Know — "Reuters' Kate Kelland Promoted False Narrative About IARC and Aaron Blair"
• NPR — "Jury Awards Terminally Ill Man $289 Million In Lawsuit Against Monsanto"
• Courthouse News Service — "Roundup Cancer Trial Verdict Upheld, but Damages Slashed"
• NBC News — "Bayer reaches over $10 billion settlement in Roundup cancer lawsuits"
• E&E News (Politico) — "Supreme Court won't derail landmark Roundup cancer verdict"
• Bloomberg — "Bayer Weighs Roundup's Demise Over Thousands of Cancer Lawsuits"
• National Agricultural Law Center — "Ninth Circuit Orders EPA to Revisit Conclusion That Glyphosate Is 'Not Likely' to Cause Cancer"
• Chemical & Engineering News — "The herbicide glyphosate gets 10 more years in the EU"