Many people assume that a government safety approval means a lawsuit is dead on arrival. With Roundup, that assumption is wrong. The Environmental Protection Agency has repeatedly stated that glyphosate, the active ingredient in Roundup, is unlikely to cause cancer in humans. Yet juries have awarded billions of dollars to plaintiffs who claim the herbicide gave them non-Hodgkin lymphoma. This confuses observers who see the EPA stance as a clean bill of health. The reality is that legal liability and regulatory approval operate under entirely different rules, and a federal finding does not erase the obligation to warn users about potential risks.
The key distinction comes down to burden of proof. Regulatory agencies like the EPA ask whether the evidence proves a substance is dangerous enough to ban or restrict. That is a high bar, and the EPA has concluded that glyphosate does not meet it. Courts hearing civil liability claims ask a different question: is it more likely than not that Roundup exposure caused this particular person’s cancer? That is known as a preponderance of the evidence standard, and it is far easier to satisfy than a scientific proof standard. You do not need certainty. You need a plausible chain of causation that outweighs other explanations by a slim margin.
Plaintiffs in Roundup lawsuits do not rely on the EPA to win. They point to other sources, most notably the International Agency for Research on Cancer, which is part of the World Health Organization. In 2015, IARC classified glyphosate as a probable human carcinogen. That classification is based on limited evidence in humans and sufficient evidence in animals. The EPA disagrees with that interpretation, but juries are allowed to hear about the IARC finding and weigh it themselves. This creates a battlefield of conflicting expert opinions. Plaintiffs bring epidemiologists who testify that large studies show a link between glyphosate and non-Hodgkin lymphoma. Defense experts respond that the studies are flawed or that the risks are minimal. The jury decides who to believe.
The first major case to go to trial was Johnson v. Monsanto in 2018. A California groundskeeper with terminal cancer received a verdict of nearly $290 million, later reduced to about $21 million on appeal. The appellate court upheld the core finding that Monsanto failed to warn about the dangers of Roundup, while tossing out punitive damages. That decision is important because it rejected Monsanto’s argument that the EPA’s approval shielded the company from liability. Courts have consistently ruled that regulatory compliance does not preempt state law claims based on failure to warn. A manufacturer can follow federal guidelines and still be liable if it knew or should have known about risks that the agency did not fully evaluate.
Another factor driving these claims is internal company documents. In litigation, plaintiffs uncovered emails and memos suggesting that Monsanto had ghostwritten scientific articles and attempted to influence regulators. These documents do not prove that glyphosate causes cancer, but they do suggest that the company acted in bad faith or at least failed to take the risk seriously. Juries often respond negatively to evidence that a corporation prioritized profit over consumer safety. That evidence transforms the case from a complex scientific debate into a story about corporate misconduct, which is much easier for a jury to grasp.
The procedural structure also matters. Roundup lawsuits are not a single class action. They are mass torts, meaning thousands of individual claims are filed separately but often consolidated for pretrial discovery. This allows each plaintiff to present their own medical history, exposure level, and diagnosis. A class action would force all plaintiffs to share the same evidence and outcome, which rarely works for cancer cases because every patient is different. Mass torts give each person a day in court or an opportunity to negotiate a settlement based on the strength of their specific claim.
Bayer, which bought Monsanto in 2018, has been fighting these cases tooth and nail. The company has won a few trials, mostly by showing that the plaintiff’s other risk factors, such as smoking or obesity, could explain the cancer. But it has also lost several, leading to a surge in new filings. Bayer initially proposed a $10 billion settlement covering many existing claims, but judges rejected it because the deal did not address future claims adequately. The company has since moved on to a different strategy: lobbying for state laws that would preempt Roundup claims entirely. Several states have introduced bills to bar failure-to-warn lawsuits for products that carry federal approval, but none have passed yet.
What does this mean for someone considering a Roundup claim? The EPA’s stance is not a legal shield for the defense. It is one piece of evidence that a jury can weigh against other evidence. A plaintiff still needs expert testimony linking glyphosate to their cancer, a solid medical history, and an estimated level of exposure. The strength of the science matters, but so does the story. Companies have lost cases where their own internal documents show they knew about cancer concerns and stayed silent. Expect more trials, more contradictory studies, and more jury verdicts that make regulators and courts look like they live in different worlds.
