Supreme Court Sides With Bayer in Roundup Cancer Warning Case
A Supreme Court ruling in Bayer’s favor on Thursday could reshape thousands of pending claims from people who say they developed cancer after using Roundup, the widely used weedkiller originally made by Monsanto.
The 7-to-2 decision overturned a $1.25 million jury award for John Durnell, a St. Louis gardener who said decades of exposure to Roundup caused him to develop non-Hodgkin lymphoma, a type of blood cancer. Durnell had argued that the company failed to adequately warn consumers about the product’s risks.
At the center of the case was a narrower legal question with potentially broad consequences of whether state-law failure-to-warn claims can move forward when the Environmental Protection Agency has allowed Roundup to be sold without a cancer warning.
Writing for the majority, Justice Brett M. Kavanaugh said the Missouri lawsuit would “require a cancer warning on Roundup’s label,” putting it at odds with the label approved under federal pesticide law. Because that state-law requirement would conflict with the federal label overseen by the E.P.A., he wrote, the claim was “expressly pre-empted” by federal law.
Kavanaugh also pointed to the pesticide law’s requirement for national consistency in labeling, writing that the Federal Insecticide, Fungicide and Rodenticide Act requires “uniformity” and bars states from imposing pesticide-labeling rules that go beyond or differ from federal requirements.
The decision is a major victory for Bayer, the German pharmaceutical and chemical company that acquired Monsanto in 2018 and inherited a sprawling wave of Roundup litigation. Thousands of similar lawsuits are still pending in state and federal courts, and Thursday’s ruling could make those claims harder to pursue.
Bayer said the decision should sharply narrow the litigation that has followed Roundup for nearly a decade, arguing that the ruling should lead courts to dismiss current warning-based claims and prevent similar failure-to-warn claims from being brought in the future. The ruling also appeared to reassure investors, with Bayer’s shares jumping sharply after the decision.
Bayer has argued that because the E.P.A. has not required a cancer warning for Roundup, the company should not face state-level lawsuits claiming it had a duty to add one. The company has maintained that the federal agency’s position should override lawsuits brought by Durnell and other plaintiffs under state law.
Government lawyers under the Trump administration backed Bayer’s position, reversing the Biden administration’s stance. They argued that once the E.P.A. determined Roundup could be sold without a cancer warning, Bayer was required to follow that labeling decision. If the company had changed the label on its own, they said, it would have violated the Federal Insecticide, Fungicide and Rodenticide Act.
That shift by the Trump administration drew sharp criticism from some supporters of the Make America Healthy Again movement, whose activists had broadly aligned with President Trump’s 2024 campaign. For them, the administration’s support for Bayer marked a break from promises to challenge corporate influence over health and food policy.
The backlash was sharpened by Robert F. Kennedy Jr.’s role, now the Secretary of Health and Human Services and a key figure for many MAHA supporters. Before joining the administration, Kennedy had been involved in litigation against Monsanto and helped win a similar case in 2018 for a man who claimed the company failed to warn consumers about glyphosate’s cancer risks.
Zen Honeycutt, founder of Moms Across America and an advocate in the MAHA movement, called the ruling “worse than treason” and said it represented a betrayal of what Trump had pledged to the movement. “It really is chemical warfare on the American people,” she said.
Alex Clark, a prominent MAHA supporter and Trump ally, also criticized the administration’s role in the case.
“Today, the Supreme Court made it impossible for people who develop cancer after using Roundup to sue Bayer for failing to warn them about the potential cancer risk. The Trump administration URGED and PLEADED the Court to reach this result to protect a FOREIGN chemical company—and it did at the expense of Americans. What happened to America First? For an administration that promised to take on corporate capture and Make America Healthy Again, this is a STUNNING betrayal. Farmers, families, and cancer patients currently in litigation with Bayer will never forget this.”
Vani Hari, the food activist and prominent MAHA voice known as “the Food Babe,” also condemned the outcome. “It’s really sickening,” she said, adding that glyphosate, Roundup’s active ingredient, “becomes now the midterm issue.”
Roundup has been sold since Monsanto developed it in the 1970s and remains one of the world’s most commonly used herbicides. Its active chemical, glyphosate, is absorbed by plants and moves into their roots, where it blocks an enzyme they need to grow.
Concerns about glyphosate have fueled one of the largest waves of product-liability litigation in U.S. history. Plaintiffs have pointed to evidence in laboratory animals, along with more limited evidence involving humans, that has suggested a possible link between glyphosate and cancer. In 2015, the World Health Organization’s International Agency for Research on Cancer classified the chemical as “probably carcinogenic to humans.”
The E.P.A., however, has reached a different conclusion in its own reviews. In February 2020, the agency said that “there are no risks of concern to human health when glyphosate is used in accordance with its current label” and that glyphosate was “unlikely” to cause cancer in humans.
Those findings were later withdrawn after a court challenge, and the agency’s review of glyphosate’s safety remains ongoing.
Kelly Ryerson, a MAHA advocate who posts online as “Glyphosate Girl,” cast the ruling as a political breach by the administration.
“Today’s SCOTUS ruling is historic. Never in history has an administration so blatantly and willingly sold out our fertility, vitality, and health to corporate interests. It is unforgivable. We will make sure all voters know exactly how this domestic chemical attack happened.”
In 2023, a jury in the Circuit Court of the City of St. Louis ruled in Durnell’s favor and awarded him $1.25 million. Bayer appealed, and the case ultimately reached the Supreme Court.
Before the case reached the high court, a Missouri appeals court had upheld the judgment in Durnell’s favor. The Supreme Court reversed that ruling and sent the case back to the lower courts for further proceedings consistent with its decision.
The justices’ ruling split the court in an unusual way. Justice Ketanji Brown Jackson, a liberal, dissented alongside Justice Neil M. Gorsuch, a conservative. In her dissent, Justice Jackson said the majority had read the federal pesticide law too broadly, leaving Durnell “without a remedy for the significant harms he has suffered.”
Jackson also said the majority had broken from what she described as the near-unanimous approach of other state and federal courts that had rejected Bayer’s preemption argument. In her view, Durnell’s claim did not impose a separate state labeling requirement but instead mirrored FIFRA’s own ban on misbranded pesticides.
Bayer praised the outcome. Brian Leake, a company spokesman, said in a statement that the decision was “good for science, farmers, and industries that depend on regulatory clarity for innovation.”
Environmental advocates, however, said the ruling would make it easier for chemical manufacturers to avoid accountability when federal labeling decisions fail to capture potential dangers.
Earthjustice, a nonprofit environmental law organization, called the decision “deeply troubling.” Patti Goldman, a lawyer for the group, said the ruling “allows Monsanto and other chemical companies to avoid responsibility when their labels leave people unprotected from serious harm.”
Moumita Basuroychowdhury is a Contributing Reporter at The National Digest. After earning an economics degree at Cornell University, she moved to NYC to pursue her MFA in creative writing. She enjoys reporting on science, business and culture news. You can reach her at moumita.b@thenationaldigest.com.
