The Roundup cases: allegations, science and a changed warning-law landscape

What plaintiffs allege

The federal cases were brought together after plaintiffs alleged that glyphosate-based Roundup products can cause non-Hodgkin lymphoma and that Monsanto failed to warn consumers and regulators about the alleged risk. Those are the allegations the JPML described when it created MDL 2741—not findings that apply to every lawsuit or every exposure.

Federal Roundup actions are centralized in the Northern District of California before Judge Vince Chhabria. JPML's August 3, 2026 report listed 3,932 pending actions and 5,322 historical actions in the MDL.

Why the science cannot be reduced to one slogan

EPA continues to state that glyphosate is not likely to be carcinogenic to humans. The agency also explains that a court vacated the human-health portion of its 2020 interim registration-review decision, EPA withdrew the rest of that decision, and the registration review is still underway.

IARC reached a different kind of conclusion in 2015, classifying glyphosate as probably carcinogenic to humans, Group 2A. IARC calls this a hazard classification: it speaks to the strength of evidence that an agent can cause cancer, not the probability that a particular exposure caused a particular person's disease.

Neither statement answers individual causation. That question depends on evidence about the person, the product and exposure, the diagnosis, competing explanations and the law governing the case.

What Monsanto argued—and what the Supreme Court decided

John Durnell alleged that long-term Roundup use caused his non-Hodgkin lymphoma and that Monsanto should have placed a cancer warning on the label. Monsanto argued that federal pesticide law preempted that Missouri failure-to-warn claim because EPA had approved the label without the warning.

On June 25, 2026, the Supreme Court agreed with Monsanto on that legal question. It held that FIFRA preempted Durnell's label-based failure-to-warn claim, reversed the Missouri appellate judgment and sent the case back for further proceedings.

The decision is important, but its boundary matters. It resolved the label-based Missouri claim before the Court. It did not decide whether Roundup caused Durnell's illness, and it did not issue a single ruling on every theory or every action in MDL 2741.

What to check next

For a specific lawsuit, use the docket number and read the complaint, the answer or motion presenting the defense, and the latest court order. For a scientific claim, note whether the source is discussing hazard, population-level risk or causation in one person. Those are different questions.