Glyphosate, one of the world’s most widely used ingredients in herbicides, is being debated at the highest levels in the United States as concerns grow over its impact on Americans’ health.

President Donald Trump issued an executive order in February to ensure an adequate supply of the chemical, while members of Congress have proposed legislation to regulate its use. Soon, the Supreme Court will hear a lawsuit addressing the widespread allegation that the chemical increases the risk of cancer.

Below is a breakdown of what you need to know about glyphosate, what politicians are saying, and why critics are opposed to its use.

What is Glyphosate?

Glyphosate is a key ingredient in Monsanto’s popular herbicide Roundup, used by farmers to inhibit the growth of weeds in their crops.

The Environmental Protection Agency (EPA) registered glyphosate as a pesticide in 1974.

Glyphosate has since become among the most widely used chemicals in agricultural production, with its use skyrocketing in the mid-1990s. That’s when Monsanto introduced “Roundup Ready” crops, which are genetically modified, allowing farmers to begin spraying their fields to kill weeds without killing the crop itself.

A 2016 study published in Environmental Sciences Europe found that no chemical comes close to such intensive and widespread use as glyphosate, which will likely remain the most widely used pesticide in the world for years.

Claims that exposure to the chemical increases the risk of cancer, coinciding with its increasing use over time, have skyrocketed.

Currently, there are more than 100,000 plaintiffs across the country seeking to hold Monsanto liable, claiming the use of Roundup caused them to develop cancer.

In a March 2015 review, the World Health Organization’s International Agency for Research on Cancer classified glyphosate as “probably carcinogenic to humans,” based on “limited” evidence of cancer in humans and “sufficient” evidence of cancer in experiments with animals.

MAHA Criticism

There is a divide among Republicans, as supporters of the Make America Healthy Again, or MAHA, movement grow increasingly frustrated with political leaders supporting glyphosate’s use.

In a Feb. 18 executive order, Trump described the chemical as vital to national defense and directed his administration to ensure there was an adequate supply.

“Lack of access to glyphosate-based herbicides would critically jeopardize agricultural productivity, adding pressure to the domestic food system, and may result in a transition of cropland to other uses due to low productivity,” his order read.

It would also provide immunity to pesticide manufacturers if Congress passed it into law.

By contrast, Health and Human Services Secretary Robert F. Kennedy Jr. previously helped secure a $289 million award from Monsanto in 2018. He represented a client who alleged Roundup caused him to develop non-Hodgkin’s lymphoma.

Years later, RFK, who has become an icon of the MAHA movement, posted a statement on X offering his support for Trump’s executive order.

Pesticides and herbicides used in farming are toxic by design, RFK’s post on X read. But the system heavily depends on these chemicals, and if farmers stop using them, the impact on the U.S. food supply would be devastating, he said.

He added that there are ongoing efforts to transition away from harmful production methods.

Despite Kennedy’s comments, MAHA supporters pushed back, and lawmakers have taken steps to try to block Trump’s executive order.

Kelly Ryerson, known online as “Glyphosate Girl,” said on X that “just as the large MAHA base begins to consider what to do at midterms, the President issues an [executive order] to expand domestic glyphosate production. The very same carcinogenic pesticide that MAHA cares about most.”

Local, State, and Federal Efforts

There are currently efforts at the state, local, and federal levels to limit the use of glyphosate.

For example, Ryerson has signaled support for a bipartisan bill introduced by Rep. Thomas Massie (R-Ky.). It would withhold funding for enforcing Trump’s order.

“If we’re Making America Healthy Again, government shouldn’t be promoting glyphosate and providing liability immunity for corporations making it,” Massie said in a March 4 post on X.

The Carlson Law Firm, which is bringing lawsuits over glyphosate, listed at least 150 cities or counties with restrictions or bans on the chemical.

In February, Florida Surgeon General Dr. Joseph Ladapo called the claims that glyphosate is critical to growing food “bollocks” and “nonsense.”

“It is possible to grow food in a sustainable way that doesn’t involve folks ingesting stuff that makes them sick,” Ladapo said at a news conference in February.

Supreme Court Case

The Supreme Court will consider a case on April 27 that could limit the ability of plaintiffs to hold Monsanto liable.

Missouri man John Durnell is alleged to have developed non-Hodgkin’s lymphoma after years of exposure to Roundup. A jury already unanimously agreed, awarding him $1.25 million and finding that Monsanto failed to comply with state law requiring a warning about cancer risks.

Monsanto told the justices the case was deeply flawed due to the legal principle of preemption, which says federal law takes precedence over lower laws when the two are in conflict.

More specifically, Monsanto said the Federal Insecticide, Fungicide, and Rodenticide Act, which authorizes the EPA to regulate pesticides, took precedence over state law. Because the EPA had already cleared the chemical for use, Monsanto argued Missouri shouldn’t be able to impose additional regulations.

In a recent amicus brief filed in the case, Trump administration officials urged the high court to side with Monsanto. It said that when the EPA registers a chemical like glyphosate, the agency has the “final word on precautionary warnings” and any “state-law claims second-guess those judgments.”

Durnell disputed that the federal law prevented Missouri from requiring warnings.

“Missouri has a right to protect its citizens from the detrimental health effects of dangerous pesticides,” his attorneys said in a brief to the court.

Bayer, the parent company of Monsanto, has welcomed the Supreme Court’s review, saying in a statement, “It is time for the U.S. legal system to establish that companies should not be punished under state laws for complying with federal warning label requirements.”

Bayer has offered $7.25 billion to settle all current and future lawsuits.