Supreme Court to hear Bayer’s appeal to block thousands of Roundup weedkiller lawsuits

The US Supreme Court agreed on Friday to hear Bayer’s bid to sharply limit lawsuits claiming that the company’s Roundup weedkiller causes cancer and potentially avert billions of dollars in damages.

The justices took up Bayer’s appeal of a lower court’s ruling in a case brought by a man who said he was diagnosed with non-Hodgkin’s lymphoma after years of exposure to Roundup. The Missouri Court of Appeals upheld a $1.25 million verdict that a St. Louis jury awarded the plaintiff, John Durnell, over his cancer diagnosis.

Bayer shares jumped almost 5% on the news that the court would hear the case. The court has yet to announce when it will hear arguments in the dispute.

In a statement, Bayer CEO Bill Anderson said the court’s decision was “an important step in our multi-pronged strategy to significantly contain this litigation.”

“It is time for the US legal system to establish that companies should not be punished under state laws for complying with federal warning label requirements,” Anderson said.

An attorney for the plaintiff did not immediately respond to a request for comment.

The Missouri Court of Appeals rejected the German pharmaceutical and biotechnology company’s contention that federal law governing pesticides bars lawsuits making claims over pesticides under state laws.

Bayer is facing similar claims from approximately 65,000 plaintiffs in state and federal courts. Roundup is among the most widely used weedkillers in the United States.

President  Trump’s administration in December urged the Supreme Court to take up Bayer’s appeal. In a brief filed at the court, US Solicitor General D. John Sauer offered the administration’s view that Bayer is correct in its reading of the law at issue.

Bayer is arguing that consumers should not be able to sue it under state law for failing to warn that Roundup increases cancer risk because the Environmental Protection Agency has found no such risk and requires no such warning. Bayer argued that federal law does not allow it to add any warning to the product beyond the EPA-approved label.

The company has made the Supreme Court a key part of its strategy to manage the claims, as a ruling that federal law preempts claims brought under state law would shut down the vast majority of the lawsuits.

Lawyers for Durnell had asked the Supreme Court to turn away Bayer’s appeal. They said Durnell relied on Bayer’s advertising and not just the label when he chose to use Roundup, and the company’s marketing failed to warn consumers of the product’s risks.

The company has paid about $10 billion to settle most of the Roundup lawsuits that were pending as of 2020, but failed to get a settlement covering future cases. New lawsuits have continued to pour in since then. Plaintiffs have said they developed non-Hodgkin’s lymphoma and other forms of cancer due to using Roundup, either at home or on the job.

Bayer, which acquired Roundup as part of its $63 billion purchase of agrochemical company Monsanto in 2018, has said that decades of studies have shown Roundup and its active ingredient, glyphosate, are safe for human use.

“EPA has repeatedly determined that glyphosate is not likely to be carcinogenic in humans, and the agency has repeatedly approved Roundup labels that did not contain cancer warnings,” Sauer said in the administration’s brief to the Supreme Court.

The company has had a mixed record at trial in the Roundup lawsuits. Bayer has prevailed in a series of Roundup trials, but it was also hit with large jury awards in the past few years, including a $2.1 billion verdict in a case in the state of Georgia in 2025.

Bayer has asked the Supreme Court to consider the Roundup litigation before, but was rebuffed in 2022. Since then, one federal appeals court agreed with the company in a split from other appeals courts.

Bayer has threatened to withdraw Roundup from the US market as it fights the litigation. The company replaced glyphosate in US consumer products with different weed-killing substances.