Supreme Court agrees to hear longstanding fight over Roundup cancer claims

(CNN) — The Supreme Court said Friday that it will decide whether tens of thousands of people claiming the pesticide Roundup caused their cancer will have a day in court, or whether a federal law that regulates pesticide labeling will effectively block their cases from moving forward.

The court’s decision to hear the case has significant practical implications for agriculture – which heavily relies on the product – and Americans who claim Monsanto violated various laws by failing to warn them about the risk of cancer. It also raises an interesting political issue for the Trump administration, which is backing Monsanto even though HHS Secretary Robert F. Kennedy Jr. has long criticized the product.

The court will likely hear arguments in the spring.

Monsanto was purchased by German-based Bayer in 2018.

The Supreme Court appeal followed a $1.25 million jury verdict in favor of John Durnell, who sued Monsanto in Missouri state court in 2019, alleging that he developed non-Hodgkin’s lymphoma after being exposed to Roundup. A state appeals court upheld that decision.

Monsanto, which has faced more than 100,000 similar claims across the country, has argued that a federal law enacted in the 1970s that gives the Environmental Protection Agency power to regulate pesticides preempts state law claims like Durnell’s. That argument, if embraced by the Supreme Court, would likely foreclose many of the pending suits against the company.

The company has already removed the active ingredient in Roundup, glyphosate, from the consumer version of its product. But glyphosate remains the central ingredient in industrial versions widely used by farmers.

The EPA under both Democratic and Republican administration has repeatedly concluded that glyphosate does not cause cancer and has declined to require cancer warnings on Roundup’s labeling. But in 2015, the International Agency for Research on Cancer classified glyphosate as an agent that is “probably carcinogenic to humans.” Several juries have sided with plaintiffs who sought damages after claiming they were diagnosed with non-Hodgkin’s lymphoma because of their exposure to the product.

As the case was pending at the Supreme Court, a scientific journal retracted a landmark study it published 25 years ago concluding that glyphosate is safe. Emails uncovered as part of other litigation against the company demonstrated Monsanto employees were heavily involved in that study, a situation the journal said raised “serious ethical concerns regarding the independence and accountability” of its authors.

“EPA has repeatedly determined that glyphosate, the world’s most widely used herbicide, does not cause cancer,” Monsanto’s attorney told the Supreme Court in an appeal filed in April. “EPA has consistently reached that conclusion after studying the extensive body of science on glyphosate for over five decades.”

Bayer on Friday applauded the Supreme Court’s decision to hear the case, saying in a statement that it is “an important step in our multi-pronged strategy to significantly contain this litigation.”

Durnell said he sprayed the weedkiller in parks near his home for years.

“The result was a deadly and incurable form of non-Hodgkin lymphoma, a blood cancer,” his attorneys told the Supreme Court. “The jury found that Roundup caused that cancer and that Monsanto was liable for Durnell’s damages.”

Monsanto claims that the Federal Insecticide, Fungicide, and Rodenticide Act preempts state labeling requirements. But Durnell has countered that he relied on off-label advertisements from the company, which he said marketed the product as safe to spray without the use of protective equipment.

The Trump administration urged the Supreme Court to take up the case in December, claiming that once the EPA has registered a pesticide a company can’t change its label without the agency’s approval. That means, the administration said, that Missouri could not tack extra requirements onto the labeling for Roundup.

While that position is consistent with the administration’s generally business-friendly approach, it represents a break with the previous position of its top health official. Kennedy was a lead attorney in one of the highest profile lawsuits seeking damages from Monsanto over Roundup.

That 2018 case saw a jury order Monsanto to pay $289 million to Dewayne Johnson, a former groundskeeper terminally ill with non-Hodgkins lymphoma. A California appellate court in 2020 upheld that verdict, but reduced the damages to $20.4 million. Johnson’s was the first of thousands of cases eventually brought against Monsanto over glyphosate’s health impact.

It was a landmark win for Kennedy, who ran for president in 2024 on a pledge to ‘Make America Healthy Again’ that included a plan to ban commonly used pesticides. After Kennedy became health secretary, he led a report that linked glyphosate and another common pesticide, atrazine, to cancer, liver complications and reproductive health disorders.

But that MAHA report just as quickly said that “American farmers rely on these products” and the Environmental Protection Agency regularly reviews their safety. A later MAHA strategy, released in September 2025, said EPA will work on targeted pesticide use, but proposed no bans or further regulation, angering some of the MAHA base.

At the same time, advocates fought for Congress to strike language in the federal budget that would shield Monsanto and other chemical manufacturers from future litigation. The provision was axed from a funding bill this January after “immense public pressure,” Maine Rep. Chellie Pingree, who fought against the measure, said in a statement.

This story has been updated with additional reporting.

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