Bayer wins U.S. Supreme Court ruling that makes it harder to sue over glyphosate in Monsanto’s Roundup

Bayer said it has won a U.S. Supreme Court case concerning lawsuits alleging harm from glyphosate, the active ingredient in Monsanto’s Roundup weedkiller. The ruling, reported June 25 by CNBC, is expected to make it more difficult for plaintiffs to pursue certain claims connected to glyphosate exposure, a chemical used widely in agriculture.

Glyphosate is widely used as a nonselective herbicide. According to CNBC’s reporting, it is the most commonly used weedkiller in agriculture, and it has been the focus of long-running litigation alleging cancer and other injuries. Plaintiffs have argued that exposure through farming and related uses created an unreasonable risk, while Bayer and other defendants have disputed the basis for those claims.

The Supreme Court’s action changes the litigation landscape by tightening the standards or procedures under which some cases can proceed. While the June 25 report emphasizes the effect on the ability to sue, it does not, in the information provided here, specify the legal tests or the exact procedural mechanism the Court used in its decision.

The decision comes amid continued scrutiny of glyphosate’s health and safety profile, and it affects not only the companies involved but also the broader network of claimants, courts, and insurers that handle mass tort filings. When Supreme Court rulings narrow access to certain legal pathways, they can reduce the number of cases that survive at early stages and can alter settlements and case management strategies across jurisdictions.

Affected plaintiffs and their attorneys are likely to face new questions about whether remaining claims must be refiled under different standards, pursued through different theories, or limited by how courts apply the Supreme Court’s guidance. Defendants, for their part, are expected to use the ruling to argue for dismissal or tighter limits on the cases covered by the decision.

Bayer’s victory indicates a continuation of the Supreme Court’s role in shaping mass tort litigation, including how lower courts handle allegations tied to widely used chemicals. Further details on which categories of claims are directly curtailed, and how lower courts apply the ruling going forward, are expected to emerge in subsequent orders and guidance from appellate courts.