The U.S. Supreme Court ruled 7-2 that federal pesticide law blocks a Missouri man’s claims that Monsanto failed to warn consumers about glyphosate, a key ingredient in Roundup. The decision, written by Justice Brett Kavanaugh and supported by the court’s major
The People vs the Poison protesters gathered at the U.S. Supreme Court on April 27. 2026. holding their message in the same place where a major fight over Roundup was about to be decided. Inside. a Missouri lawsuit centered on who gets to set pesticide warnings and what happens when state courts disagree with federal rules.
On Tuesday, the Supreme Court agreed to shield Monsanto from liability over its popular weed killer Roundup, handing a victory to the company’s new owner as it faces thousands of costly suits from people who claim the product’s key ingredient caused their cancers.
The case was filed by Missouri resident John Durnell. Its central question was who decides what should appear on a pesticide or insecticide label—and whether a federal law overrides state claims.
In a 7-2 opinion written by Justice Brett Kavanaugh. the court said the Federal Insecticide. Fungicide. and Rodenticide Act. or FIFRA. expressly preempts state law and Monsanto’s failure-to-warn claims about glyphosate. Justice Ketanji Brown Jackson filed a dissenting opinion, joined by Justice Neil Gorsuch.
Monsanto, now owned by Bayer, argued that federal law places label-setting authority in the hands of the U.S. Environmental Protection Agency rather than states. Its lawyer. former Solicitor General Paul Clement. told the Supreme Court that “there’s a need for a single. uniform standard. ” and that FIFRA puts the EPA in charge. He also argued during oral argument in April that, “You shouldn’t let a single Missouri jury second-guess that judgment.”.
The court’s majority agreed. Kavanaugh wrote that because Durnell’s state tort claim would impose a pesticide labeling requirement “in addition to or different from” the label required by EPA, FIFRA expressly preempts Durnell’s claim.
The current U.S. Solicitor General, John Sauer, sided with Monsanto, as did the majority of the Supreme Court justices.
Legal experts said the ruling could significantly narrow Monsanto’s liability in tens of thousands of cases moving through the courts.
But Durnell’s side urged the justices to let state juries play a role in weighing whether Monsanto adequately warned consumers about glyphosate’s dangers. A lawyer for Durnell argued that there is room for state juries to weigh in on Monsanto’s alleged failure to warn.
Ashley Keller told the justices that Congress has been debating a “golden shield” for the company as part of the farm bill. Until Congress acts, Keller said, state juries could and should still be able to evaluate such cases.
Jackson, dissenting, agreed that states should be allowed to consider those warning claims. In her dissent, she said the majority misunderstood FIFRA’s requirements. She also argued that adding a cancer warning wouldn’t conflict with the law.
“In accepting Monsanto’s argument 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,” Jackson wrote.
The courtroom arguments came as protesters had already filled the area around the Supreme Court in late April, showing support for people who say they were harmed by the weed killer and other chemicals, in allegiance with the Make America Healthy Again movement.
President Trump has also signed an executive order to boost domestic production of glyphosate. a move that has contributed to a rupture between the White House and some MAHA supporters—underscoring how the fight over Roundup is not only legal. but political and personal for many of the people watching the Supreme Court decide what comes next.
U.S. Supreme Court Monsanto Bayer Roundup glyphosate FIFRA John Durnell Brett Kavanaugh Ketanji Brown Jackson Neil Gorsuch preemption EPA labeling lawsuits Make America Healthy Again MAHA President Trump