The Supreme Court has declined to hear a lawsuit against Bayer, effectively shutting down claims that its Roundup weedkiller causes cancer.
The court’s decision is likely to determine the future of thousands of similar lawsuits against the company.
Bayer has faced mounting legal pressure over Roundup, with plaintiffs alleging glyphosate, the active ingredient, led to their illnesses.
The justices did not comment on the merits of the case, leaving the lower court ruling in place.
That ruling had favored Bayer, finding federal law shielded the company from state-level failure-to-warn claims.
The decision removes a significant legal cloud for Bayer, which has previously sought to settle large portions of the litigation.
Many pending cases will now likely be resolved in favor of the company, limiting further payouts.
Legal experts say the ruling sets a precedent that could prevent future lawsuits based on similar arguments.
Bayer has maintained that Roundup is safe when used as directed and cites regulatory approvals worldwide.
Opponents argue the ruling shields corporations from accountability for alleged health risks.
