Roundup

Roundup is a glyphosate-based herbicide, produced by Monsanto. It is a commonly used weed killer that is sold around the world. Many countries around the world have banned, or implemented policies that regulate the use glyphosate. Monsanto has been accused of tampering and ghostwriting with scientific tests. In 2015 the International Agency for Research on Cancer (IARC) classified the glyphosates used in Monsanto products as “probably carcinogenic,” though this finding has not been confirmed by the EU assessment or the World Health Organization. The EPA’s “assessment found no other meaningful risks to human health when the product is used according to the pesticide label.” While in 2020, there were approximately 13,400 Roundup-related lawsuits filed against Monsanto, as of March of 2026, this number reached an upwards of 100,000 Roundup-related lawsuits. A recent ruling by the Supreme Court, however, has blocked lawsuits related to Bayer (Monsanto’s parent company) failing to warn consumers of the potential link to cancer.

Background

Glyphosate is the most commonly used herbicide worldwide and is used to kill weeds. It is routinely sprayed on crops such as wheat, barley, oats, canola, flax, and peas.

In the 1970s, a Monsanto scientist discovered the chemical formulation for glyphosate. The company then patented the molecule. Glyphosate was brought on the market under the name Roundup. When glyphosate first became more popular, it’s attractiveness came from its convenience for farmers and wide variety of applications. However, the patent expired in 2000, and has since been used in other agrochemical companies’ products.

In the 1990s, the state of New York went after Monsanto for false advertising. In 1996, the state’s attorney general claimed the ads, which stated that their glyphosate-based products were “safer than table salt”, were misleading. Monsanto agreed to change their advertisements to no longer include the claims that the products were nearly non-toxic to mammals, birds, and fish. Also, they could no longer claim the weed killer was biodegradable or environmentally friendly.

The part of a plant that glyphosate targets is called the shikimate pathway, which brings together the plant’s aromatic amino acids. This pathway is not found in animals.
Monsanto also invented Roundup Ready Crops, genetically modified crops that were resistant to the glyphosate used in Roundup. This meant that farmers could plant crops that would not be affected by using the herbicide, killing the weeds and preserving the crop.

According to the Journal of Environmental and Analytical Toxicology, there is a connection between health problems- such as obesity and heart disease- to glyphosate. The study shows that traces of the compound can be found on the leaves of plants and in rain water. It was also shown that people who were chronically ill had significantly higher levels of glyphosate in their system, compared to the general population. In 2015, the World Health Organization classified glyphosate as likely carcinogenic and several studies have indicated that glyphosate can be harmful to the reproductive system, gut health, and other internal processes. In 2017, the state of California listed glyphosate as a chemical that causes cancer.

In 2017, the state of California listed glyphosate as a chemical that causes cancer.

Bayer/Monsanto no longer includes glyphosate in Roundup products sold to residential lawn and garden consumers but continues to sell it in the agricultural market. Mounting litigation was threatening to force the company to stop selling the herbicide altogether, raising concerns about food supply chain disruptions.

Malawi, Thailand, Vietnam, Sri Lanka, Oman, Kuwait, the United Arab Emirates, Bahrain, Qatar, Saudi Arabia, St. Vincent and the Grenadines, Bermuda, Austria, Belgium, the Czech Republic, Denmark, France, Italy, and Netherlands have legislation that regulates the use of glyphosate.

The EPA has determined that the causal link between glyphosate and cancer is unlikely in humans. The Supreme Court ruled in June 2026 that Bayer could not be sued for failing to warn consumers of the potential risk because of its unlikely nature, essentially blocking thousands of claims against the company.

Injuries and Damages

There are currently thousands of lawsuits against Roundup in which the plaintiff claims the product gave them an illness. In the three cases that have already gone to court, Monsanto was found guilty of mislabeling their products. Roundup did not have proper cancerous warnings, resulting in the diagnosis of non-Hodgkin lymphoma in the four plaintiffs.

Traces of glyphosate have been found in food and rainwater. However, the consequences of ingesting this compound is not fully known. The chemical targets aromatic amino compounds not found in mammals. There have also been reports that glyphosate can inhabit other amino compounds, that humans do possess. Glyphosate interacts and changes how certain enzymes work in the human body, which may lead to ailments such as depression and autism. Glyphosate had toxic effects on certain cells in vitro. The full, long-term effects of consuming glyphosate are not yet known.

Roundup was banned in France in January of 2019 after a court case in Lyon found that Monsanto had not properly labeled the product. The company was found to have not warned customers of the possible cancerous effects of the herbicide.

Legislation and Regulation

In February 2026, President Trump signed an executive order to label glyphosate products as necessary for national security and defense purposes. He advocated for more protections and lesser regulatory actions towards companies producing glyphosate products. As part of the Defense Production Act, Trump directed the government to ensure an adequate amount of this product remained in supply and hoped to shield manufacturers from litigation in this highly contentious arena. A variety of different legislative and regulatory policies have also been proposed by various state actors.

Organics first pesticide policies
As of 2022, 150 cities in 25 states across the United States have implemented organics first pesticide policies. Tucson, Arizona became the first city to implement this policy on city property in 2018. The policy is centered on banning or restricting glyphosate on other private or public lands. Some states, such as Montana, which rely heavily on agriculture are slow to implement Roundup restrictions.

EPA Regulation
Proposed management measure under docket # EPA-HQ-OPP-2009-0361. The US Environmental Protection Agency has not found any “meaningful risks to human health” when studying glyphosate, if it is being used correctly. In 2020 the EPA again declared that Glyphosate is not carcinogenic. While the use of glyphosate has not been found to cause any human health risks, the EPA is currently researching the ecological risks the herbicide possesses. On April 30, 2019, the EPA released a statement about their next steps in the review process for herbicide glyphosate. The new proposed action would involve better management to help farmers use the product effectively and efficiently, according to EPA Administrator Andrew Wheeler. In 2020, after a challenge in the United States Court of Appeals for the Ninth Circuit, the EPA withdrew its Glyphosate Interim Decision (ID). This ID failed to identity any human risks as a consequence of glyphosate, but it cited environmental concerns. The EPA continues to find no major health risk posed by glyphosate and stated that glyphosate has “low toxicity” for humans.

Congress
In March of 2019, Congresswoman Rosa DeLauro of Connecticut introduced the Keep Food Safe from Glyphosate Act. This bill was in response to the United States Department of Agriculture (USDA) failing to monitor glyphosate in their yearly pesticide residue survey. This act would require the USDA to test annually for glyphosate residue on commonly consumed foods. It would also stop the practice of spraying glyphosate as a pre-harvest drying agent and ensure that the Environmental Protection Agency lower the level of allowed glyphosate residue on oats.

New York
New York State Senator Brad Hoylman proposed two bills to the state legislature in August of 2018 which would ban the use and sale of glyphosate. These bills, S126 and S127, were introduced shortly after a jury in California ruled that Roundup caused cancer.

France
In January of 2019, a court in Lyon, France ruled that regulators in the French environmental agency ANSES previously failed to take safety concerns into account when clearing Roundup for use. In the lawsuit, environmentalist argued that glyphosate was a carcinogen, citing an article by the World Health Organization. Following the court case, the ANSES banned the sale and distribution of Roundup Pro 360.

Liability and Insurance

Monsanto is responsible for any damages caused by their products. Under the Uniform Product Liability Act, the company is responsible for personal injury, death, or property damage that happened because of any section of the manufacturing process. In the case of Monsanto, they are responsible for the deteriorating health of people who became ill after using their product. There are studies that show that Roundup and its chemical compound of glyphosate cause cancer, raspatory ailments, and heart disease. It can harm enzymes, creating a higher probability of becoming sick. By failing to accurately warn consumers of potential risks, the company is liable.

Three separate juries in Northern California have found Monsanto and Roundup to be liable for the cancer each plaintiff was diagnosed with. The company is culpable in the health issues that can arise after the use of their product.

Litigation

There are currently around 100,000 lawsuits regarding Roundup. There is a class-action suit filed in the Los Angeles Superior Court against Monsanto using false advertising. There are lawyers across the United States who claim to specialize in Roundup lawsuits. Many of these cases are still on going. There have been three separate court cases that have gone to trial filed against Monsanto in which the plaintiff claimed to have developed non-Hodgkin Lymphoma after using Roundup. All three of those were won by the petitioner. There are currently thousands of other suits filed against the company of people claiming to have become ill due to the herbicide, and specifically citing concerns that Roundup caused cancer.

Monsanto and Bayer have also settled several of the cases brought against them. In 2024, out of the 167,000 claims against them, 113000 of them were settled. In August 2025, Bayer added billions of dollars to their litigation reserve to handle the new wave of upcoming litigation around the harms caused by Roundup. The Supreme Court decided in Monsanto Co. v. Durnell, on June 25, 2026, that federal pesticide labeling laws (FIFRA) prevent States from imposing additional or different requirements. EPA guidelines find the link to cancer unlikely, so Bayer Monsanto’s labels complied with FIFRA. This means that all state-level suits against Bayer Monsanto are effectively blocked. The ruling is a huge win for the chemical conglomerate, as FIFRA’s preemption of state regulations provides sweeping protection to Bayer Monsanto’s warning labels.

Missouri Appellate Court Decision
On May 28, 2025, a Missouri Appeals Court made a major decision regarding Roundup liability after 3 plaintiffs alleged that Roundup was the cause of non-Hodgkin Lymphoma. The earlier Ninth Circuit decision came into contention for being introduced at the trial stage, but eventually, the court ultimately held in favor of plaintiffs, holding in favor of a $611 million verdict against Monsanto.

Bayer AG
Close to 100,000 U.S. lawsuits were filed against the German drugs and pesticides makers, claiming that its widely used Roundup caused cancer. Bayer contends that Roundup is highly regulated, and safe and important for farmer use. After more than a year of talks, Bayer AG has agreed to pay up to $10.9 billion to settle the cases. The suits have plummeted the company’s share price, down 29% since 2018, and market value. Three cases will continue through the appeals process and are not covered by the settlement. Bayer will continue to sell Roundup, and future cases will be governed by a class agreement, including the establishment of an independent scientific panel, subject to court approval.

Dewayne Johnson v. Monsanto Company
The first Roundup lawsuit that went to trial. The lawsuit alleges that Mr. Johnson developed Non-Hodgkin Lymphoma after contact with after exposure to Roundup. Mr. Johnson was a school groundskeeper in Northern California. The lawsuits made the claim that the herbicides used by Monsanto were not safe, as the company claimed. Monsanto was aware of the dangers and hid this information from the public. The decision was made on August 10, 2018, finding Monsanto guilty of failing to give the information on the cancer risk of the product. The jury awarded Mr. Johnson $289 million in damages. On appeal, the compensatory award to Mr. Johnson was reduced, and the punitive damages were reduced in turn according to the reduction in future noneconomic damages.

Edwin Hardeman v. Monsanto Company
Edwin Hardeman filed suit alleging that Roundup was a "substantial factor" in causing his non-Hodgkin lymphoma. Mr. Hardeman had been using the product for over two decades on his farm in Sonoma, California. The lawsuit proved that Roundup’s design was defective, it lacked cancer warnings and Monsanto was negligent. The jury awarded Mr. Hardeman $80 million in damages, which was later reduced to $20 million.

Pilliod v. Monsanto Company
This is the third Roundup lawsuit to go to court. Mr. and Mrs. Pilliod claimed that they were diagnosed with cancer after using Monsanto’s product for over three decades. After an initial award of $2 billion in punitive damages, the awards were reduced to total awards of $31 and $56 million to Mr. and Mrs. Pilliod, respectively.

Monsanto Company v. Durnell
While the lower courts in Hardeman and Pilliod found that state-level failure-to-warn regulations were not preempted by FIFRA, the Supreme Court ruled to the contrary in June 2026. This decision has the effect of blocking all state-level failure-to-warn litigation against Bayer Monsanto due to the company’s compliance with EPA regulations.

Future Outlook

Even though Bayer Monsanto lost three cases in court and has been forced to pay millions in losses, there is no conclusive evidence that Roundup and the glyphosate in it are carcinogenic. Further, the major win at the Supreme Court provides sweeping protection against state-level failure-to-warn claims. Even independent studies conducted on the effects of glyphosate have been inconclusive. While Monsanto’s main court argument is that the science is inconclusive, juries have still decided beyond a reasonable doubt that Monsanto is guilty of corporate negligence.

Researchers say the work that still needs to be done must be transparent to avoid either side claiming biases in the data. Yet, politicians may act before the science has a chance to. Cities across the United States have implemented policies shifting away from the use of pesticides contain glyphosate. The court cases have brought up a host of issues pertaining to the use of the chemical, including the question of whether agrochemicals should be used at all in the production of our food.