On June 25, 2026, the Supreme Court ruled 7-2 in Monsanto Co. v. Durnell that the federal pesticide law, FIFRA, preempts state-law claims that Monsanto failed to warn consumers that its weed killer Roundup could cause cancer. Writing for the majority, Justice Brett Kavanaugh said that because the EPA has repeatedly concluded glyphosate is not likely to cause cancer and has approved Roundup's label without a cancer warning, “as a matter of federal law, Monsanto legally must use a label without a cancer warning unless and until EPA approves or requires a change.” The majority crossed ideological lines, with Justices Sotomayor and Kagan joining; Justices Ketanji Brown Jackson and Neil Gorsuch dissented. Monsanto is owned by the German company Bayer. The ruling is expected to block thousands of failure-to-warn suits, CBS News reported, though other claims, such as design-defect and negligent-testing claims, can still proceed.
The Trump administration backed Monsanto in the case, with the Justice Department arguing in a filing that federal law gives the EPA responsibility for deciding whether pesticide warnings are needed. In February, Trump signed an executive order to boost production of glyphosate-based herbicides, framing it as protecting the food supply (see Trump Invokes Defense Production Act for Glyphosate, Whose Only Domestic Supplier Gave $1 Million to His Inauguration).
The outcome angered parts of the “Make America Healthy Again” movement aligned with Health Secretary Robert F. Kennedy Jr., which has campaigned against glyphosate. Activist Vani Hari wrote on X, “I am literally sick. This is a devastating blow to every family that trusted our justice system.” Podcaster Alex Clark wrote that the administration “URGED and PLEADED the Court to reach this result to protect a FOREIGN chemical company,” and asked, “What happened to America First?” The episode set the administration's support for a major agrochemical company against the anti-pesticide voters RFK Jr. brought into the coalition.
Correction (October 2, 2026): an earlier version of this entry said the ruling shields Monsanto from lawsuits by people who say Roundup gave them cancer. The Court held that state failure-to-warn claims are preempted; other kinds of claims can still proceed. The title and summary now say so.