RoundUp history
Roundup, the most popular and profitable weed killer ever sold, uses glyphosate as its most active ingredient. Glyphosate is toxic to most broadleaf plants and grasses. It kills most plants it comes into contact with, instead of targeting certain weeds or plants.
Monsanto, a now defunct company, developed the product. Because glyphosate kills anything it touches, Monsanto developed plant seeds that were genetically modified to resist the damage of Roundup. This is when residential Roundup sales skyrocketed.
However, as the years went on, science questioned the safety of glyphosate. Studies have shown that the chemical might cause illness to humans and cause damage to the environment. The International Agency for Research on Cancer categorizes glyphosate as possibly carcinogenic to humans—essentially, the IARC is saying this toxin may cause cancer.
In 2018, Roundup was purchased by Bayer. By then, consumers had filed thousands of lawsuits linking Roundup to cancer. The most common cancer associated with Roundup is non-Hodgkin’s lymphoma. Bayer committed to begin in 2023 replacing “its glyphosate-based products in the U.S. residential Lawn & Garden market with new formulations that rely on alternative active ingredients.”
Roundup Cancer Lawsuits
Monsanto has settled over 100,000 Roundup lawsuits, paying out about $11 billion as of May 2022. There are still 30,000 lawsuits pending. This includes 4,000 cases in multidistrict litigation (MDL) in California. MDL cases are not class-action suits. Instead they group cases together so that instead of answering the same question repeatedly in each separate lawsuit, the courts can resolve some specific issues for all of them at once.
In June 2022, the Ninth Circuit filed a decision in a Roundup case. In the court’s opinion, the Ninth Circuit urged the Environmental Protection Agency (EPA) to reconsider its conclusion that Roundup does not cause substantial harm to people or the environment. Also in that month, the Supreme Court dismissed an appeal by Bayer in another Roundup case.
In July 2022, the 11th Circuit ruled that Bayer had failed to adequately warn about the risk of cancer from Roundup.
Latest Developments in Roundup Lawsuits
Latest Developments in Roundup Lawsuits (as of May 2025)
The Roundup lawsuits, centered on allegations that the herbicide’s active ingredient, glyphosate, causes cancer—particularly non-Hodgkin’s lymphoma—continue to evolve with significant legal and financial implications for Bayer, which acquired Monsanto in 2018. Below is a concise summary of the most recent developments based on available information:
- Major Verdicts in 2025:
- March 2025, Georgia: A jury ordered Bayer to pay over $2.1 billion to plaintiff John Barnes, who developed non-Hodgkin’s lymphoma after using Roundup. The award included $65 million in compensatory damages and $2 billion in punitive damages, signaling strong juror disapproval of Bayer’s handling of glyphosate risks. Bayer plans to appeal, arguing the verdict contradicts scientific evidence. This verdict caused Bayer’s stock to drop nearly 9% in Frankfurt trading.
- October 2024, Philadelphia: A jury awarded $78 million to a Pennsylvania resident with non-Hodgkin’s lymphoma, including $3 million in compensatory damages and $75 million in punitive damages, interrupting Bayer’s recent courtroom wins in the region.
- January 2024, Pennsylvania: A landmark $2.25 billion verdict was awarded to John McKivison, who claimed Roundup caused his non-Hodgkin’s lymphoma after 20 years of use. The verdict, including $2 billion in punitive damages, was described as a condemnation of Monsanto’s “50 years of misconduct.”
- Multidistrict Litigation (MDL) and Case Volume:
- As of February 2025, the federal MDL in Northern California, overseen by Judge Vince Chhabria, had 4,414 pending cases, with a slight increase from 4,373 in December 2024. While the MDL remains active, state courts are seeing more action, with larger verdicts driving plaintiff interest.
- Approximately 165,000 lawsuits have been filed nationwide, with around 54,000 still unresolved as of mid-2024. Bayer has settled over 100,000 claims for nearly $11 billion since 2020, but new cases continue to emerge.
- Bayer’s Legal and Legislative Strategies:
- Appeals and Preemption: Bayer is aggressively appealing large verdicts, citing the EPA’s 2020 stance that glyphosate is “unlikely to be a human carcinogen.” The company argues that state-based failure-to-warn claims are preempted by federal labeling laws under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). A circuit split exists, with the Third Circuit (Pennsylvania) ruling in favor of preemption in 2024, while the Eleventh Circuit (Georgia) rejected it, prompting Bayer to petition the U.S. Supreme Court in April 2025. A favorable Supreme Court ruling could significantly limit future lawsuits.
- State Legislation: Bayer is lobbying for state laws to shield it from lawsuits. Georgia passed SB 144 in March 2025, following North Dakota, to protect Bayer from claims alleging failure to warn about cancer risks when labels comply with EPA regulations. These laws aim to reduce Bayer’s liability but do not affect existing lawsuits.
- Settlement Approach: Bayer has allocated around $16 billion for settlements, including $2 billion for future claims. However, since filing its Supreme Court petition, Bayer has paused settlement talks with plaintiff firms representing significant claim volumes, opting to fight cases in court.
- Scientific and Regulatory Developments:
- New Research: A 2025 study in Ecotoxicology and Environmental Safety suggested glyphosate negatively impacts human reproductive health, contributing to infertility. Another study in Proceedings of the National Academy of Sciences linked glyphosate exposure to adverse perinatal outcomes, such as lower birth weights. These findings bolster plaintiff arguments.
- EPA Reassessment: Following a 2022 court order, the EPA is reassessing glyphosate’s cancer and ecological risks, with no final decision as of May 2025. The International Agency for Research on Cancer (IARC) maintains its 2015 classification of glyphosate as a “probable human carcinogen,” a key point in lawsuits.
- Industry vs. Independent Studies: Non-industry studies, like a University of Washington review showing a 41% increased risk of non-Hodgkin’s lymphoma with heavy glyphosate exposure, contrast with industry-funded research claiming safety, fueling the ongoing debate.
- Litigation Trends and Plaintiff Eligibility:
- Lawsuits primarily focus on non-Hodgkin’s lymphoma, but other cancers like leukemia and B-cell lymphoma are also cited. Agricultural workers, landscapers, and those with prolonged exposure are considered most eligible.
- State courts, particularly in Pennsylvania, Georgia, and California, are delivering massive verdicts, pressuring Bayer to settle. However, some verdicts have been reduced on appeal (e.g., a 2023 San Diego award dropped from $332 million to $28 million).
- Statutes of limitations (1–3 years from diagnosis or awareness of a Roundup-cancer link) urge potential plaintiffs to act quickly.
- Public and Corporate Impact:
- Bayer’s stock has declined 70% since acquiring Monsanto, exacerbated by recent verdicts. The company faces financial strain, having spent over $10 billion on settlements while defending glyphosate’s safety.
- Bayer phased out glyphosate-based Roundup for U.S. residential markets in 2023 but continues its use in agriculture, developing alternative herbicides to mitigate future litigation risks.