Monsanto Wins First Roundup® (Glyphosate) Trial After the U. S. Supreme Court’s Durnell Decision

On October 30, 2026, a Missouri circuit court jury reached a unanimous defense verdict in favor of Monsanto Company (Monsanto) in the three-plaintiff case of Theresa Aretino, et al. v. Monsanto Company (Case 20SL-CC03676, Aretino), the first Roundup^® trial to take place since the U.S. Supreme Court’s landmark ruling in Monsanto Company v. Durnell (Durnell). The jury found for Monsanto on the design defect, fraud, and negligence claims that each of the three plaintiffs pursued at trial following the Supreme Court’s favorable decision in Durnell, which preempted their failure-to-warn claims for the active ingredient glyphosate.

First Glyphosate Trial After the Durnell Decision

For more than a decade, litigation over glyphosate-based herbicides has sat at the intersection of federal pesticide regulation, state tort law, scientific risk assessment, and broader debates over the role of juries in evaluating product safety. The Supreme Court’s June 25, 2026, decision in Durnell represents the Court’s most significant interpretation of the Federal Insecticide, Fungicide, and Rodenticide Act’s (FIFRA) preemption provision since Bates v. Dow Agrosciences LLC. The landmark ruling determined that state-law warnings requiring a specific labeling requirement “in addition to or different from” those approved by the U.S. Environmental Protection Agency (EPA) are preempted under FIFRA, as discussed in Bergeson & Campbell, P.C.’s (B&C) July 9, 2026, memorandum. After the Durnell decision, with failure-to-warn claims no longer available, the Aretino plaintiffs pursued design defect, fraud, and negligence claims. The Missouri verdict in favor of Monsanto marks the initial judicial test of whether plaintiffs can provide sufficient proof for design defect, fraud, and negligence claims following the Supreme Court’s Durnell ruling.

Background on Glyphosate’s Carcinogenic Potential

Glyphosate is a broad-spectrum herbicide registered by EPA for use on many crops and in non-crop sites such as forests, rights-of-way, pasture and rangeland, recreational and wildlife-management areas, and residential settings. Virtually all global authoritative bodies have determined glyphosate does not cause cancer. The International Agency for Research on Cancer (IARC) and detractors claim otherwise, however, and the debate continues.

In EPA’s 2017 human health risk assessment, EPA did not identify risks of concern with glyphosate uses, including for cancer, from dietary and drinking-water exposure or residential exposure. As discussed in B&C’s September 10, 2026, blog post, EPA is now updating the human health risk assessment to incorporate more recent, scientifically relevant published literature (including epidemiological data), which will inform EPA’s decisions moving forward. EPA is partnering with the U.S. Department of Health and Human Services (HHS) to strengthen scientific coordination for the risk assessment of glyphosate, as discussed in B&C’s September 29, 2026, blog post. EPA also convened an independent scientific review panel in 2016 and solicited stakeholder input on scientific issues related to the carcinogenic potential of glyphosate. The conclusions of the scientific review panel can be found in EPA’s Scientific Advisory Panel Report for glyphosate. Under the Federal Food, Drug, and Cosmetic Act (FFDCA), EPA establishes pesticide tolerances (maximum residue limits) on food when it determines there is a “reasonable certainty that no harm will result from aggregate exposure to the pesticide residue” when used according to its label.

EPA states that it anticipates completing its evaluation of glyphosate’s carcinogenic potential and human health risk assessment in late 2026, and EPA intends to hold a public webinar in early 2027 to provide an overview of the updated human health risk assessment. More information on glyphosate can be found at EPA’s Glyphosate Registration Review and on EPA’s webpage on glyphosate.

Commentary

As expected, the Supreme Court’s decision in Durnell is reshaping the litigation landscape for pesticides registered by EPA. The Missouri verdict in favor of Monsanto marks the initial judicial test of whether plaintiffs can provide sufficient proof for design defect, fraud, and negligence claims following the Supreme Court’s Durnell ruling. Based on the result of the Missouri circuit court verdict, plaintiffs who wish to pursue design defect, fraud, and negligence claims in court following the Durnell ruling may face challenges in the future. Future litigation for design defect, fraud, and negligence claims may affect everyone involved — not just for glyphosate, but across the entire pesticide industry.