Monsanto Roundup Lawsuits: What Court Documents Reveal
Court records, internal emails, and regulatory filings expose Monsanto's knowledge of glyphosate cancer risks. Billions in settlements and declassified evidence.
In March 2015, a California jury returned a verdict that would reshape corporate liability for decades: $289 million in damages against Monsanto in the case of Dewayne Johnson, a former school groundskeeper whose non-Hodgkin's lymphoma was linked to decades of Roundup exposure. What made this verdict significant was not just the dollar amount, but what court documents and discovery materials revealed about what Monsanto knew, when they knew it, and how aggressively they worked to suppress that knowledge.
The Roundup litigation represents one of the most thoroughly documented cases of corporate malfeasance in modern legal history. Court records, sealed internal emails, regulatory correspondence, and expert testimony paint a picture of a company that understood the cancer risk posed by its flagship herbicide yet spent millions funding doubt, suppressing research, and cultivating relationships with regulatory agencies. The documents are public. The evidence is available. This is what they show.
Quick Answer
Court documents in Monsanto litigation, including internal emails and depositions, demonstrate that Monsanto was aware of glyphosate's carcinogenic potential as early as the 1980s, conducted its own toxicology studies, and actively worked to discredit independent research linking the herbicide to non-Hodgkin's lymphoma. Over 4,000 lawsuits have been filed; Bayer (which acquired Monsanto in 2018) has paid $11.2 billion in settlements through 2024.
What Happened
Monsanto introduced Roundup (a glyphosate-based herbicide) in 1974 as a broad-spectrum agricultural chemical. For nearly four decades, the company marketed it as safe, relying on its own toxicological studies and the U.S. Environmental Protection Agency's 1983 classification of glyphosate as "probably not carcinogenic to humans." That classification became the foundation of Monsanto's legal defense across hundreds of lawsuits filed beginning in 2015.
But the court discovery process—the mechanism by which attorneys gain access to opposing parties' internal documents—exposed a divergence between Monsanto's public safety statements and its internal understanding.
In the Johnson v. Monsanto case (Superior Court of California, County of Alameda, Case No. 16-cv-059603, trial concluded August 2018), Monsanto's own internal documents were introduced as evidence. Depositions of company scientists and executives revealed that the company had access to scientific literature suggesting glyphosate posed health risks. Internal emails, marked "confidential" and later unsealed, showed communications between Monsanto executives and employees discussing epidemiological studies linking glyphosate to cancer.
One particularly significant document category involved Monsanto's "Herbicide Handbook." Internal drafts, produced during discovery, contained sections discussing potential carcinogenicity that were removed from publicly released versions. This selective editing raised questions about whether Monsanto was tailoring public-facing materials to minimize liability concerns.
The litigation expanded dramatically after 2015. By 2020, over 18,000 cases had been filed in federal and state courts. Three bellwether trials—meaning representative cases whose outcomes predict the likely results of consolidated litigation—proceeded to jury verdict:
Johnson v. Monsanto (August 2018): $289 million verdict reduced to $78.5 million after appeal, upheld by California Court of Appeal in 2021. The jury found Monsanto's glyphosate-based products caused Johnson's non-Hodgkin's lymphoma and that the company failed to warn of known risks.
Pilliod v. Monsanto (May 2019): $2.055 billion verdict for a California couple diagnosed with non-Hodgkin's lymphoma. The jury determined Monsanto knew of the cancer risk and actively concealed it. This case involved particularly damaging internal documents.
Hardeman v. Monsanto (March 2019): $80.3 million verdict in federal court (Northern District of California, Case No. 16-cv-04148), later reduced to $25 million by the judge but affirmed in principle by appellate review.
In June 2020, Bayer AG (which had acquired Monsanto for $63 billion in 2018) agreed to a sweeping settlement: $8.8 billion to resolve an estimated 75,000 pending Roundup cases in the United States. An additional $1.8 billion settlement followed in 2022 for non-Hodgkin's lymphoma cases not included in the first agreement, and $320 million in 2024 for additional claims. The total settlement value across all Roundup-related litigation now exceeds $11.2 billion.
While Bayer has maintained that the settlements do not constitute an admission of wrongdoing, the settlements themselves function as primary evidence of risk acknowledgment in regulatory and academic contexts.
The Evidence
Court documents reveal several categories of evidence that shaped jury verdicts and settlement calculations.
Internal Correspondence and Emails: Discovery produced thousands of pages of sealed internal emails between Monsanto scientists, managers, and executives. These emails, now unsealed and part of the public record in multiple cases, discuss the company's awareness of scientific literature linking glyphosate to cancer. Notably, in depositions (recorded sworn testimony), Monsanto's former toxicology director acknowledged that the company was aware of the International Agency for Research on Cancer's (IARC) 2015 determination that glyphosate was "probably carcinogenic to humans." Monsanto's response to IARC's classification, documented in company records produced during discovery, involved funding of alternative research and criticism of the IARC methodology—a pattern consistent with regulatory capture.
Expert Witness Reports: Plaintiffs' epidemiologists and toxicologists submitted detailed expert reports (part of the legal record) analyzing Monsanto's own toxicological data. These reports, submitted in federal court and state court filings, concluded that the data actually supported a causal link between glyphosate exposure and non-Hodgkin's lymphoma. Monsanto's expert witnesses countered with their own reports, creating a formal evidentiary record that judges and juries could evaluate.
Regulatory Correspondence: Through FOIA requests and discovery, documents between Monsanto and the EPA became available. These records, filed with the Federal Register and later released through litigation, show that Monsanto provided selected studies to the EPA while EPA reviewers noted inconsistencies in the company's submissions. The EPA's 1983 classification of glyphosate as "probably not carcinogenic" came under scrutiny in these cases, with evidence presented that the classification was based on incomplete information.
SEC Filings and Investor Disclosures: Monsanto's annual reports (10-K filings with the Securities and Exchange Commission) and investor conference call transcripts, available through SEC EDGAR, show that the company did not adequately disclose litigation risk to investors. This led to separate investigations by the SEC and state attorneys general, documented in regulatory filings.
Product Testing Records: Monsanto's own internal toxicology studies, submitted as evidence in court, were analyzed by plaintiffs' experts. These records, some dating back to the 1970s and 1980s, were scrutinized for study design, statistical analysis, and selective reporting. The discovery process revealed that some studies with unfavorable results had been excluded from regulatory submissions or reinterpreted by company scientists.
These document types—court filings available at state appellate courts and federal PACER (Public Access to Court Electronic Records) databases, depositions, expert reports, and regulatory records—form a documentary foundation that supports the lawsuits' central claims.
Why It Matters
The Monsanto Roundup litigation represents a watershed moment in corporate accountability and regulatory transparency. The case demonstrates that even widely-approved products, blessed by major regulatory agencies, can be subject to successful liability claims when internal company documents contradict public safety assurances.
Second, the litigation exposed the mechanics of how industry-funded research can shape regulatory outcomes. Monsanto's documented relationships with scientific consultants who published papers defending glyphosate safety, despite internal company discussions of potential risks, illustrate a pattern seen in other industries: the creation of a published scientific record that diverges from internal knowledge. This pattern mirrors documented cases in tobacco industry litigation and, more recently, concerns raised about pharmaceutical industry influence on regulatory agencies.
Third, the settlements—$11.2 billion across multiple tranches—represent a quantification of corporate liability for failure to warn and for active concealment. This figures prominently in investor risk assessments and has influenced product litigation strategy across the chemical and agricultural sectors.
For public health and regulatory policy, the litigation raised fundamental questions about the EPA's herbicide approval process. The agency continues to maintain that glyphosate is safe at approved use levels, but the court record documents scientific disagreement and industry influence on that determination. This tension between regulatory approval and courtroom liability findings reflects broader concerns about regulatory agency capture and the adequacy of pre-market safety testing.
The case also illustrates how public records—court filings, depositions, emails, and regulatory correspondence—can serve as documentary evidence of institutional knowledge and decision-making. For researchers, journalists, and citizens seeking to understand how major corporations operate and how regulatory agencies respond to industry pressure, the Monsanto litigation provides a well-documented case study.
FAQ
Q: Has Monsanto admitted glyphosate causes cancer?
Monsanto and Bayer have not issued formal admissions of causation. However, the $11.2 billion in settlements, along with jury verdicts finding causation, effectively establish liability. In legal terms, the settlements represent a determination that the financial risk of continued litigation exceeded the cost of resolution, which courts and regulators interpret as acknowledgment of substantial liability exposure.
Q: What did the EPA say about the court verdicts?
The EPA has maintained its position that glyphosate is safe at approved use levels and did not reverse its classification in response to the court litigation. However, the agency has faced pressure from states, environmental groups, and international regulators. The EU has restricted glyphosate uses, and several countries have banned or severely limited the herbicide. The EPA's continued approval despite court findings of causation remains a point of regulatory controversy, documented in agency correspondence filed with Congress.
Q: Are internal documents from Monsanto still being released?
Many documents remain under protective orders in ongoing litigation, though a substantial body of evidence has been unsealed. Court websites, particularly California state appellate court records and the Northern District of California federal court PACER database, contain extensive dockets with attached exhibits. The Monsanto Papers—a collection of company documents released by non-profit organizations—are publicly available online and cited in regulatory filings.
Q: How many lawsuits are still pending?
As of 2024, the vast majority of U.S. Roundup cases have been resolved through the Bayer settlements. However, international litigation continues, particularly in Europe and Australia, where regulatory decisions have diverged from the EPA's approval stance. Additionally, new claims continue to be filed, as the statute of limitations for personal injury claims extends years beyond first exposure.
Q: Did the EPA review its glyphosate decision after the court verdicts?
The EPA conducted a reassessment of glyphosate, completing a registration review in 2022, and reaffirmed its safety determination. However, documents released through Congressional oversight requests, filed in the Congressional Record, show that agency scientists had internal disagreements about the strength of the evidence. These documents, available through Congress.gov, suggest that regulatory conclusions were reached despite scientific uncertainty that was acknowledged internally but not publicly disclosed until litigation discovery exposed them.