The Roundup lawsuit: glyphosate, non-Hodgkin lymphoma, and the Supreme Court case that could end it

The Roundup litigation is one of the largest mass torts in U.S. history. More than 170,000 claims have been filed alleging that long-term exposure to Roundup weedkiller caused non-Hodgkin lymphoma (NHL), a type of blood cancer. The active ingredient at issue is glyphosate, an herbicide developed by Monsanto in the 1970s and marketed under the Roundup brand. Bayer acquired Monsanto in 2018 and assumed all its liabilities, including the rapidly expanding talc litigation that turned into a billion-dollar problem within months.

As of May 2026, Bayer has resolved roughly 100,000 Roundup claims and paid approximately $11 billion in settlements and verdicts. Tens of thousands of claims remain pending. The litigation operates on multiple tracks simultaneously: a federal multidistrict litigation, state court litigation across multiple jurisdictions, a proposed $7.25 billion class action settlement filed in Missouri state court in February 2026, and a Supreme Court case (Monsanto v. Durnell) that could fundamentally reshape the legal framework if Bayer wins.

The procedural posture in 2026 has both clarity and uncertainty. The class settlement provides a defined compensation framework for many claimants. The Supreme Court case could either end most Roundup litigation (if Bayer wins on federal preemption) or leave the existing framework intact (if plaintiffs win). The June 4, 2026 opt-out deadline for the class settlement and the Supreme Court ruling expected by early July 2026 create critical decision points for current and future claimants.

This is the science connecting glyphosate to non-Hodgkin lymphoma, the legal framework operating across federal and state courts, the proposed class settlement and what it offers, the Supreme Court case and its potential impact, and what's actually filing-eligible now.

The science: glyphosate and non-Hodgkin lymphoma

Glyphosate is the world's most widely used herbicide, applied to billions of acres globally each year. Monsanto introduced it as Roundup in 1974, and after the patent expired in 2000, glyphosate became a generic active ingredient used in many herbicide products. Roundup remains a brand name for glyphosate-based products marketed by what's now Bayer Crop Science.

The scientific evaluation of glyphosate's cancer risk has produced contradictory conclusions from major regulatory bodies:

The International Agency for Research on Cancer (IARC), part of the World Health Organization, classified glyphosate as "probably carcinogenic to humans" (Group 2A) in March 2015. The IARC monograph found "sufficient evidence" of carcinogenicity in experimental animals and "limited evidence" in humans. The human evidence focused on associations between occupational glyphosate exposure (especially among agricultural workers) and non-Hodgkin lymphoma.

The U.S. Environmental Protection Agency (EPA) has consistently concluded that glyphosate is "not likely to be carcinogenic to humans" when used as directed. The EPA's interim registration review in 2020 reaffirmed this conclusion, and the agency continues to maintain that glyphosate-based herbicides can be used safely.

The European Food Safety Authority (EFSA) and the European Chemicals Agency (ECHA) have generally concurred with the EPA's safety assessment, though the European Union has periodically considered restrictions.

The U.S. 9th Circuit Court of Appeals ordered the EPA to reconsider its glyphosate safety conclusion in 2022, finding that "most studies EPA examined indicated that human exposure to glyphosate is associated with an at least somewhat increased risk of developing NHL," which contradicted the EPA's "not likely to cause cancer" finding.

The disagreement among regulators creates the legal landscape: U.S. plaintiffs sue under state tort law alleging Bayer/Monsanto should have warned of cancer risks, while Bayer defends by pointing to EPA's safety conclusion and the federal pesticide labeling framework. The Supreme Court case will resolve whether the federal framework preempts state law claims, which is the central legal question for the entire litigation.

The specific cancer at issue is non-Hodgkin lymphoma. Plaintiffs typically present with diffuse large B-cell lymphoma, follicular lymphoma, or other NHL subtypes following years to decades of Roundup use. The strongest cases involve agricultural workers, landscapers, groundskeepers, and others with sustained occupational exposure. Residential users (home gardeners) have viable cases when the exposure history is sufficient.

The legal framework: MDL 2741 and state courts

The federal litigation is consolidated in MDL 2741 (In re Roundup Products Liability Litigation), centralized in the U.S. District Court for the Northern District of California before Judge Vince Chhabria. The MDL was established in 2016 and has handled the major procedural and expert evidence rulings shaping the broader litigation. We cover the MDL framework generally in our overview of how mass tort settlements work.

As of May 2026, approximately 3,887 cases remain active in MDL 2741. The number is small relative to total claims because most Roundup litigation has migrated to state courts. Three factors drove this migration: state courts often allow procedural advantages (such as broader joinder rules), state law claims sometimes have stronger remedies than federal law parallels, and several state court judges have developed expertise in Roundup litigation that makes those venues attractive for plaintiffs.

Major state courts hearing Roundup litigation include the Circuit Court of the City of St. Louis (Missouri), Philadelphia County Court of Common Pleas (Pennsylvania), and various California Superior Courts. State court verdicts have produced both major plaintiff wins and notable defense verdicts; the trial record is mixed but generally favorable to plaintiffs in the highest-profile cases.

Notable verdicts shaping the litigation:

August 2018: Dewayne Johnson, a former school groundskeeper with NHL, won a $289 million verdict in California state court. The verdict was eventually reduced to approximately $20 million on appeal but established the litigation's viability.

Several subsequent verdicts in the $100 million to $2.25 billion range, some of which were reduced on appeal.

The McKivison case in 2024 produced a $2.25 billion verdict ($250 million compensatory plus $2 billion punitive), later reduced to $400 million on appeal.

The Caranci case in 2023 produced a $175 million verdict in Philadelphia, which Bayer is appealing.

The Barnes case in 2024 produced a $2.065 billion verdict ($65 million compensatory plus $2 billion punitive) involving a plaintiff with NHL after Roundup exposure.

Defense verdicts have also occurred. Roundup trials have produced verdicts on both sides; the pattern reflects the contested nature of the scientific and causation evidence.

The proposed $7.25 billion class settlement

In February 2026, Monsanto announced a proposed nationwide class settlement intended to resolve current and future Roundup claims alleging non-Hodgkin lymphoma. The settlement was filed in the Circuit Court of the City of St. Louis, Missouri, where the court has granted preliminary approval. Final approval is scheduled for July 2026, after the Supreme Court is expected to rule on Monsanto v. Durnell.

The settlement structure:

Class definition: persons who used Roundup or other glyphosate-based herbicides before February 17, 2026 (the settlement filing date) AND were diagnosed with NHL before the end of a 16-year period following final approval of the agreement. The class includes both currently injured plaintiffs and future plaintiffs who develop NHL during the next 16 years.

Compensation structure: tiered based on exposure level, age at diagnosis, and NHL type. Specific payment ranges have not been publicly disclosed but the settlement is funded over 21 years.

Total settlement value: $7.25 billion.

Class representatives and supporting plaintiff counsel: Holland Law Firm, Ketchmark & McCreight, Motley Rice, Seeger Weiss, Waters Kraus Paul & Siegel, and Williams Hart & Boundas. These law firms support the settlement.

Opt-out deadline: June 4, 2026. Class members who want to preserve their right to pursue individual lawsuits must formally opt out by this date. If a class member does nothing, they remain in the settlement by default.

The settlement has critics. Some plaintiffs' attorneys argue the per-plaintiff compensation is inadequate compared to potential trial verdicts. Approximately 250 plaintiffs with claims pending in MDL 2741 are not bound by the settlement unless they choose to join.

Judge Vince Chhabria (the MDL judge) issued an order in May 2026 stating that even if the settlement receives final approval and survives appellate review, it would not prevent his court from exercising authority over MDL cases. This creates an unusual procedural posture where the settlement covers many cases but doesn't necessarily bind all of them.

The Supreme Court case: Monsanto v. Durnell

The U.S. Supreme Court is reviewing Monsanto Company v. Durnell, No. 24-1068, with oral argument heard on April 27, 2026 and a ruling expected by early July 2026.

The case stems from a lawsuit filed by John Durnell, a St. Louis resident who used Roundup for neighborhood beautification work for years, later developed NHL, and sued Monsanto in Missouri state court in 2019. A Missouri jury awarded Durnell $1.25 million in 2023. The Missouri Court of Appeals affirmed the verdict in February 2025. Monsanto petitioned the Supreme Court for certiorari, and the Court granted review.

The legal issue: whether the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) preempts state tort claims that pesticide manufacturers should have warned of cancer risks not required by the EPA.

Bayer's argument: Because the EPA has consistently determined that glyphosate does not require a cancer warning, state tort suits requiring such a warning are preempted by federal law. Monsanto could not legally place a cancer warning on Roundup labels without EPA approval, and the EPA has never required one.

Durnell's argument: A state tort lawsuit for failing to warn is not the same as a state imposing a labeling rule. FIFRA does not preempt the right of individuals to sue under state law for failing to warn of known risks. The EPA registration decision does not have preemptive force over state tort law.

The lower courts have split sharply on this question across various Roundup cases. The Supreme Court took the case to resolve the split.

The stakes are enormous. A ruling in Bayer's favor would essentially make labeling failure-to-warn claims no longer viable, blocking the legal theory underlying most Roundup litigation. A ruling in Durnell's favor would mean the existing litigation framework continues unchanged.

The case attracted substantial amicus briefing on both sides. Twenty-two states filed amicus briefs supporting Durnell; three states (Texas, Florida, and Ohio) filed in support of Monsanto. Environmental health, consumer, and farmworker advocacy organizations filed supporting Durnell, as did a group of former EPA officials.

The Court already narrowed the scope of the question it will consider, but the ultimate opinion could be broad or tailored depending on how the justices resolve the underlying issues. The decision will fundamentally shape the trajectory of the Roundup litigation regardless of which way it goes.

Eligibility for filing

The Roundup litigation framework remains open for new filers, but the procedural decisions are more complex than for typical mass torts because of the pending settlement and Supreme Court case.

You may have a viable claim if:

You used Roundup or other glyphosate-based herbicides over a substantial period (typically multiple years, with longer exposure history producing stronger cases).

You were diagnosed with non-Hodgkin lymphoma or a related cancer (multiple myeloma, hairy cell leukemia, and certain other blood cancers have appeared in Roundup litigation, though NHL is the dominant claim type).

Your exposure and diagnosis fall within the relevant statute of limitations for your state. Statutes of limitation typically run 2 to 4 years from the date you knew or should have known of the connection between Roundup exposure and your cancer.

You can document the exposure history (occupation records for agricultural/landscaping workers, purchase records for home users, witness statements, photographs).

The strongest cases involve well-documented sustained exposure (occupational use over many years) and clear NHL diagnoses with timely medical records.

The strategic decision is more complex than for typical filings because of the class settlement. Class members who do nothing remain in the settlement by default. To preserve the right to sue individually, the petitioner must formally opt out by June 4, 2026. The opt-out decision depends on the strength of the individual case versus the certainty of the settlement framework.

The Supreme Court decision compounds the uncertainty. A Bayer victory in Durnell would likely defeat individual lawsuits but should not affect the settlement (which resolves claims regardless of legal theory). A Durnell victory would maintain the existing litigation framework, in which strong individual cases may produce verdicts well above settlement values.

What's not eligible

Several categories don't fit the current Roundup litigation framework:

Cancers other than NHL (and the narrow related categories). The litigation is structured around blood cancers with established scientific links to glyphosate exposure. Cases involving other cancer types (lung cancer, skin cancer, etc.) generally don't proceed under the current framework.

Cases beyond the statute of limitations. State limits are strict, and Roundup cases with delayed diagnoses sometimes fall outside the filing window. The discovery rule in some states extends the deadline to when the plaintiff knew or should have known of the cancer-pesticide connection, but this requires fact-specific analysis.

Cases without documentable exposure. Cases where the plaintiff used unspecified herbicides (rather than glyphosate-based products specifically), or cases without supporting documentation of exposure, are difficult to prove.

Brief or occasional exposure cases. The strongest scientific evidence supports cases involving long-term sustained exposure. Cases involving a few isolated applications typically don't fit the litigation framework.

What to do if you may have a claim

Consult with a mass tort attorney experienced in Roundup cases. Most attorneys offer free consultations and work on contingency. The attorney can evaluate whether your facts fit the framework and advise on the opt-out decision with respect to the class settlement.

Make the opt-out decision before June 4, 2026 if you want to preserve individual claim rights. The strategic analysis: stay in the settlement and accept the structured compensation, or opt out and pursue an individual claim potentially worth more (but with uncertainty given the Supreme Court case). The decision is fact-specific and worth professional consultation.

Monitor the Supreme Court ruling. The Monsanto v. Durnell decision will fundamentally affect the legal viability of Roundup claims. Plaintiffs and counsel are watching for the decision because it determines whether individual lawsuits remain viable going forward.

Gather documentation. Medical records confirming NHL diagnosis (or related cancer). Pathology reports. Treatment records. Exposure documentation: occupational records, purchase records, photographs, witness statements. The longer the documented exposure history, the stronger the case.

Don't delay filing. Statutes of limitation are strict, and the opt-out deadline for the class settlement is approaching. Action by June 4, 2026 is necessary to preserve maximum optionality.

The Roundup litigation represents one of the most complex and high-stakes mass torts in U.S. history. Bayer has paid over $11 billion to resolve claims and may pay billions more through the proposed class settlement and any continued individual litigation. The Supreme Court decision in 2026 will reshape the legal landscape. For people diagnosed with non-Hodgkin lymphoma after substantial Roundup exposure, the legal framework provides multiple paths to recovery, though the strategic decisions are more nuanced than they were in earlier phases of the litigation. The procedural windows are closing, and action within the next few months will determine which options remain available.