U.S. Backs Bayer in Supreme Court Battle Over Roundup Cancer Lawsuits

The Trump administration has thrown its support behind Bayer as the company urges the U.S. Supreme Court to review thousands of lawsuits alleging its Roundup weedkiller causes cancer. In a filing submitted by U.S. Solicitor General D. John Sauer, the administration argued that federal pesticide regulations should override state-level claims, reinforcing Bayer’s position that its product labels comply with long-established federal standards.

Bayer is seeking to overturn a lower court ruling that upheld a $1.25 million verdict for Missouri plaintiff John Durnell, who linked his non-Hodgkin’s lymphoma diagnosis to long-term Roundup exposure. The company currently faces more than 67,000 similar lawsuits nationwide. Bayer maintains that extensive scientific research and decades of Environmental Protection Agency (EPA) reviews show glyphosate—the active ingredient in Roundup—is safe when used as directed.

According to Sauer, allowing state courts to require different warning labels would undermine the EPA’s authority and lead to inconsistent regulatory standards. The EPA has repeatedly found that glyphosate is “not likely to be carcinogenic to humans,” and has approved labels without cancer warnings. Pro-business groups, including the U.S. Chamber of Commerce, also back Bayer, warning that upholding the ruling could expand liability for companies that comply with federal law.

Attorneys for Durnell urged the Supreme Court to reject Bayer’s appeal, arguing that the plaintiff relied not only on product labels but also on the company’s marketing, which failed to warn consumers of potential health risks.

Roundup remains one of the most widely used herbicides in the United States. While Bayer paid approximately $10 billion in 2020 to settle earlier claims, new lawsuits continue to emerge. The company has experienced mixed outcomes in court, including a massive $2.1 billion Georgia verdict that was later settled. As litigation intensifies, Bayer has warned that it may pull Roundup from the U.S. market and has already replaced glyphosate in consumer formulations with alternative weedkillers.