The Roundup class action lawsuit refers to a series of high-profile legal cases filed against Monsanto Company, and subsequently Bayer after its acquisition of Monsanto, alleging that the widely used herbicide Roundup causes serious health issues, particularly non-Hodgkin’s lymphoma (NHL). This litigation has evolved over many years into one of the largest mass tort litigations in U.S. history, involving hundreds of thousands of plaintiffs and billions of dollars in settlements and damages.
Background of Roundup and Health Concerns
Roundup, introduced by Monsanto in 1974, is a glyphosate-based weed killer that became the most widely used herbicide globally. Glyphosate works by targeting the shikimate pathway—an enzymatic process essential to plants but previously asserted not to exist in humans or animals.
However, numerous scientific studies and health reports began raising concerns that glyphosate exposure might be linked to non-Hodgkin’s lymphoma and other cancers. International bodies like the International Agency for Research on Cancer (IARC) classified glyphosate as a probable human carcinogen. These findings prompted thousands to file lawsuits accusing Monsanto of hiding these risks.
Initial Lawsuits and Multidistrict Litigation (MDL)
The first significant waves of Roundup lawsuits emerged in the mid-2010s. Plaintiffs alleged Monsanto knew about glyphosate’s dangers but failed to warn consumers adequately. These cases were consolidated into the U.S. District Court for the Northern District of California as MDL 2741 to streamline discovery and pretrial procedures.
Early trials resulted in landmark verdicts including millions awarded to plaintiffs diagnosed with NHL after using Roundup. Notable cases include Dewayne “Lee” Johnson, who won a $289 million verdict in 2018 (later reduced on appeal), and others who received multi-million dollar compensations.
Class Action and Consumer Claims
Beyond personal injury claims, several class action lawsuits targeted Monsanto’s labeling and marketing practices. Filed by consumers and purchasers, these suits accused Monsanto of deceptive advertising—claiming Roundup “targets an enzyme found only in plants” but ignoring evidence that the enzyme affects human gut and mucosal bacteria vital for health.
Plaintiffs in these class actions sought refunds or reimbursement for purchases of Roundup products, arguing they were misled about product safety and impacts. These cases aimed to hold Monsanto accountable beyond individuals suffering cancer, addressing widespread consumer protection issues.
Large Verdicts and Impacts on Monsanto/Bayer
Over years of trials, Monsanto and Bayer faced punitive damages exceeding hundreds of millions in multiple verdicts. For example, in 2023, Missouri juries awarded over $1.5 billion combined damages to three former Roundup users with NHL.
These staggering awards put financial strain on Bayer, the Monsanto parent, which announced setting aside $16 billion to settle ongoing claims. Bayer’s stock price suffered significant declines amid litigation concerns, impacting investor confidence.
Scientific and Legal Debates
Monsanto consistently contested the allegations, citing regulatory agency approvals and studies suggesting glyphosate’s safety when used as directed. They argued that observed correlations between Roundup and cancer were inconclusive and relied on “junk science.”
Courts wrestled with complex issues including causation proof, scientific reliability, state versus federal law conflicts, and regulatory preemption debates under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).
Recent Legal Developments and Settlements (2024-2025)
By 2024 and early 2025, Bayer resolved numerous cases through settlements totaling billions, though tens of thousands remained pending. Courts in various jurisdictions issued rulings impacting claim eligibility, damages calculations, and settlement administration.
Recent jury trials continued awarding significant verdicts, including a $2 billion damages award in Georgia in 2025, underscoring ongoing risks for Bayer despite settlements.
What This Means for Consumers and Future Litigation
Individuals diagnosed with NHL or related conditions related to Roundup exposure remain eligible to pursue claims, often through specialized law firms experienced in mass tort litigations.
The litigation has raised the bar for chemical and agricultural product safety, increasing scrutiny from regulators and public health advocates worldwide.
Conclusion
The Roundup class action lawsuit is a landmark in environmental and pharmaceutical litigation, blending science, law, and corporate responsibility debates. It highlights the profound consequences of inadequate risk disclosures and the power of the legal system to hold corporations accountable.
As Bayer navigates these complex legal challenges, the Roundup saga signals a critical turning point in how society balances agrochemical benefits with public health protections.
