WASHINGTON, D.C. — The U.S. Supreme Court will hear arguments Monday in a case over whether glyphosate manufacturer Monsanto can be held liable under federal pesticide law for failing to warn consumers about cancer risks. The case could weaken the ability of consumers to sue companies for failing to warn of product risks.

The dispute centers on glyphosate, a weed-killing chemical used in the Roundup brand and other herbicide products. Monsanto, now part of the German conglomerate Bayer, introduced glyphosate in the 1970s and has spent the last decade fighting more than 100,000 lawsuits claiming it failed to warn customers of cancer risks. The company maintains that its products do not cause cancer.

Glyphosate has been scientifically linked to cancer in multiple studies, and an arm of the World Health Organization classified it as a probable human carcinogen in 2015. The Environmental Protection Agency's position is that glyphosate is "unlikely" to be carcinogenic.

Monsanto is asking the court to rule that under the Federal Insecticide, Fungicide, and Rodenticide Act, it cannot be held liable for failing to warn of a cancer risk if the EPA has not found such a risk exists and has not required such a warning. Bayer has said a favorable ruling will help it put an end to the litigation. President Donald Trump's solicitor general will deliver oral arguments favoring Monsanto. In February 2026, Trump issued an executive order seeking to protect the production of glyphosate herbicides.

A group of former EPA officials filed an amici brief arguing against Monsanto's position. Among them is Jim Jones, who served as assistant administrator for the EPA's office of chemical safety and pollution prevention under Barack Obama. "It's the perspective I've held throughout my career at EPA. I think it is the correct one," Jones said. Lawrence Ebner, general counsel for the Atlantic Legal Foundation, which is backing Monsanto, offered a competing view. "If you have a pesticide label with a zillion different warnings, how is the user supposed to know the ones that really matter, the ones that EPA really has … determined are necessary?" Ebner said.

A Maha-led rally outside the courthouse on Monday has been organized to protest against Monsanto. Vani Hari, a health advocate and organizer of the People v Poison rally, said: "The Trump administration should know that siding with Bayer over American families is a losing position. People expect leadership that puts their health first – not policies that protect corporations from being held responsible."