Supreme Court Roundup Weedkiller Case Could Tear MAHA Apart

The Supreme Court will hear arguments Monday in the Roundup weedkiller case, where tens of thousands of lawsuits have been brought against the manufacturer Bayer, with accusations that exposure to the chemical left claimants with cancer.

The case was picked up by the court earlier this year, after Monsanto, the original producer of the glyphosate-infused herbicide asked to overturn the results of a lawsuit that forced it to pay over $1 million to a claimant who alleged that he developed non-Hodgkin lymphoma because of his exposure to Roundup.

The court will be deciding whether to grant pesticide makers immunity from failure-to-warn claims-lawsuits alleging that exposure to the chemical resulted in adverse impacts on health, if it is not required for them to label products with health impacts under U.S. Environmental Protection Agency (EPA) rules.

The hearing could also have serious implications for Health Secretary Robert F. Kennedy Jr.’s “Make America Healthy Again” campaign, which stands firmly against the use of pesticides generally. Kennedy himself has warned of the wide-ranging harm of glyphosate-the chemical in Roundup.

However, President Donald Trump’s administration has passed an order that will see glyphosate usage and supply increased in an “America-first” policy, leaving the health secretary caught between the president and many of his own supporters who have long-called for the ban of the weedkiller as the hearing is set to take place.

Newsweek contacted the Department of Health and Human Services (HHS) outside of regular working hours via email for comment.

What Is Glyphosate?

Glyphosate, the key ingredient in Roundup, is the most widely used herbicide in the U.S. and the world, according to the U.S. Geological Survey (USGS). The chemical has also been detected in 66 of 70 U.S. streams and rivers, according to the USGS.

Since glyphosate‑based products entered the market, Bayer, which acquired original producer Monsanto in 2018, has faced thousands of lawsuits alleging the company did not adequately warn consumers that its weedkiller could pose cancer risks. Earlier this year, the agrochemical giant proposed a $7.25-billion settlement aimed at resolving those claims.

Settlement documents show that roughly 200,000 claims related to Roundup have been brought against Bayer, including more than 125,000 filed since 2015.

While the EPA has determined that there are “no risks of concern to human health when glyphosate is used in accordance with its current label,” and that it is “unlikely to be a human carcinogen,” the International Agency for Research on Cancer (IARC) believes differently.

The IARC has previously concluded that glyphosate is "probably carcinogenic to humans," citing "strong" evidence of genotoxicity for both the active ingredient itself and commercial glyphosate formulations. This was an evaluation based on around 1,000 studies, conducted by independent experts who were not influenced by commercial interests.

Genotoxicity is a property in certain substances that can damage the genetic material in a cell, which can lead to mutations and diseases such as cancer.

Other research and scientific reviews have linked glyphosate exposure to an elevated risk of non‑Hodgkin lymphoma, a cancer affecting the lymphatic system. A 2020 study found that people exposed to glyphosate‑based herbicides experienced a 41 percent increase in risk of developing the disease.

The Debate Around the Weedkiller

Given the research and warnings relating to the chemical, many-including groups aligned with the MAHA movement-are against the use of the herbicide.

A group of women who call themselves “MAHA Moms” has been outraged by the Trump administration’s support of the chemical.

The president signed an executive order earlier this year calling for an increase in supply of glyphosate-based herbicides, which he said play a “critical role” in America's agricultural landscape, adding that a lack of access to the chemicals would “critically jeopardize agricultural productivity” and the country’s food system.

Kennedy himself has also supported Trump’s order. The HHS previously told Newsweek, echoing a statement from Kennedy, that “Donald Trump's Executive Order puts America first where it matters most-our defense readiness and our food supply. We must safeguard America's national security first, because all of our priorities depend on it.”

Though he has also said the order was “not something I was particularly happy with-to put it mildly.”

Kennedy has been previously vocal with his views on the chemical. In 2024, he wrote on X that glyphosate is “one of the likely culprits in America's chronic disease epidemic,” and previously said in an interview with Joe Rogan that use of the chemical “is something every American should be concerned about.”

Will It Tear MAHA Apart?

The MAHA campaign stands firmly on improving public health to reduce chronic disease through the implementation of new guidelines and policy overhaul regarding American diet, environment and medicine. Kennedy has also been a major proponent of the view that chemicals in the environment are contributing to chronic health problems in children.

The debate around glyphosate therefore puts him in a rather awkward position. He is now having to balance the direction of his own campaign, which is largely against the use of pesticides and many of his supporters who stand strongly against glyphosate, but support Trump’s “America-first” initiatives, which in this case, encourages the use of glyphosate.

The internal tension between “America-first” and “health-first” initiatives is also being felt more widely in Congress, with lawmakers raising their concerns about glyphosate ahead of the Supreme Court hearing. Republican Anna Paulina Luna, a U.S. representative for Florida, wrote on X: “Glyphosate is making Americans sick. The people that are the poorest are consuming the highest amounts. It is poison. Literally.”

As it draws closer to the hearing, tension remains high over how this decision will impact the MAHA movement.

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This story was originally published April 27, 2026 at 6:29 AM.