U.S. Supreme Court Sides With Monsanto Over Glyphosate Labeling

On June 25, 2026, with a 7-2 ruling in favor of Monsanto in the case of Monsanto Company v. Durnell, the U.S. Supreme Court blocked thousands of lawsuits against the makers of the weed killer Roundup.

Monsanto was acquired in 2018 by Bayer, and Bayer's CEO, Bill Anderson, hailed the decision in a statement as “good for American farmers who help feed the world. It provides the regulatory clarity necessary for innovators like us to develop the agricultural tools that guarantee an affordable food supply.” The statement welcomed “law that supports science,” comparing it to the frustrating patchwork of case law that led to “uncertainties for manufacturers, farmers, and consumers alike.”

In its decision, the Supreme Court absolved the manufacturer of the need to label Roundup as carcinogenic. The case began as a failure-to-warn tort suit in Missouri brought by John Durnell, a longtime Roundup user who claimed he had contracted non-Hodgkin lymphoma after years of exposure. A Missouri jury found in favor of Durnell in 2023.

Monsanto objected to Durnell's claims and appealed to the Supreme Court. In 2022, the U.S. Environmental Protection Agency (EPA) had declared glyphosate, a main ingredient in Roundup, “not likely to be carcinogenic to humans,” citing data from the International Agency for Research on Cancer (IARC). The Supreme Court granted Monsanto certiorari, agreeing to hear its argument that the decision of a federal agency, namely the EPA, and federal law, in this case the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), must hold precedence over the rulings of a state-level civil court.

The majority opinion, penned by Justice Brett Kavanaugh, argued that “FIFRA's preemption clause prohibits states from imposing any pesticide labeling requirements that are 'in addition to or different from' the federal labeling requirements.” The opinion stressed the rigor of the approval process for new chemicals under FIFRA and the difficulty that comes with relabeling. It also reinforced the EPA's determination that glyphosates are safe for public use.

“In 1974, EPA first registered glyphosate-based pesticides and approved Roundup's label without a cancer warning,” wrote Kavanaugh. “In 1991 and for the more than three decades since, EPA has repeatedly re-evaluated glyphosate and has repeatedly concluded that glyphosate is not likely to cause cancer.” This is enough, the opinion stated, to negate Durnell's citation of the FIFRA provision that “in no event shall registration … be construed as a defense for the commission of any offense under this subchapter.” Justices Ketanji Brown Jackson and Neil Gorsuch dissented, with Brown Jackson writing, “The court departs from the near-unanimous view of the many state and federal courts that have rejected this preemption argument. In my view, the majority should have joined that chorus. Durnell's failure-to-warn claim is not 'in addition to or different from' FIFRA's mandates; it is equivalent to FIFRA's key labeling requirement-the misbranding prohibition.”

“In accepting Monsanto's argument,” she added, “and holding that Durnell's failure-to-warn claim is preempted, the court misunderstands FIFRA's requirements, misinterprets the scope of FIFRA's preemption, and ultimately leaves Durnell without a remedy for the significant harms he has suffered.”

Federal legislators weighed in, with Rep. Thomas Massie (R-KY) took to X to denounce what he saw as a “blatant travesty of justice.” Across the aisle, Sen. Cory Booker (D-NJ) claimed the decision would let Bayer “poison us with impunity.”

Around 200,000 Roundup-related claims have been made against Monsanto/Bayer, mostly from home users. Bayer has stopped using glyphosate in Roundup sold in the U.S. residential lawn and garden market.

“Ultimately, the effect of the majority's interpretation is both remarkable and regrettable, for it unjustifiably closes the courthouse doors to state tort plaintiffs like Durnell,” wrote Brown Jackson.