What to know about glyphosate, the herbicide behind a Trump executive order that’s angered MAHA moms

Secretary of Health and Human Services Robert F. Kennedy Jr., appears before the Senate Finance Committee, on Capitol Hill in Washington, Sept. 4, 2025. (AP Photo/Mark Schiefelbein, file)

Supporters of the “Make America Healthy Again” strategy have long railed against pesticides, making opposition to them a pillar of the movement.

But an executive order issued by U.S. President Donald Trump last week collides with that long-held stance.

The order states that glyphosate — an herbicide found in Roundup, the world’s most widely used weed killer — is “central to American economic and national security” and calls for an adequate domestic supply.

Glyphosate inhibits protein synthesis in plants and microorganisms, leading to their death. Scientists can genetically modify corn, soybeans and cotton — three field crops that account for the vast majority of glyphosate use in the United States — to choose which crops survive and which die after glyphosate treatment.

US Health and Human Services Secretary Robert F. Kennedy Jr., a key figure in the MAHA movement, has long opposed glyphosate-based pesticides. In 2018, as an attorney, Kennedy helped win a lawsuit alleging that maker Monsanto knew that Roundup caused cancer. He reiterated last month on Katie Miller’s podcast that “I believe glyphosate causes cancer.”

But Kennedy sounded a different tone.

“Donald Trump’s executive order puts America first where it matters most — our defense readiness and our food supply,” the HHS chief said in a statement. “We must safeguard America’s national security first, because all of our priorities depend on it. When hostile actors control critical inputs, they weaken our security. By expanding domestic production, we close that gap and protect American families.”

The day before Trump’s order was announced, Monsanto’s owner, Bayer, proposed a $7.25 billion settlement to resolve current and future claims alleging that the product causes cancer. The settlement would not include an admission of liability or wrongdoing, and Monsanto maintains that there is no evidence that glyphosate causes cancer.

“Experts and regulators worldwide have concluded that glyphosate-based products can be used safely as directed,” the company states.

Moms Across America, a nonprofit that supports the MAHA agenda, has advocated for glyphosate bans and called the new executive order “outrageous,” saying it could shield Monsanto — the only domestic producer of glyphosate — from lawsuits over products sold in compliance with the order.

“I was outraged. I was actually sick to my stomach,” Zen Honeycutt, the group’s founder and executive director, told CNN’s Pamela Brown on The Situation Room on Monday. “When I saw this executive order, it was basically a love letter to glyphosate.”

Kennedy said this month on Theo Von’s podcast that an outright glyphosate ban “would put out of business 80% of our farmers.” He agreed that the nation is “dependent upon something that we know makes us sick” and said his agency is “doing a lot of work” to find alternatives to glyphosate.

Republican Rep. Thomas Massie has introduced a bill that he says would “undo” the order, and Moms Across America called the Kentucky lawmaker a “true health hero.”

Health concerns of glyphosate

In 2015, the World Health Organization classified glyphosate as a probable carcinogen.

WHO “puts other everyday things like drinking hot beverages, a barber’s occupational exposure and eating red meat at the same level of safety hazard as glyphosate,” Monsanto says on its website.

Two large meta-analyses have found that people exposed to glyphosate have a higher risk of cancer. One of those studies estimated that the risk of non-Hodgkin lymphoma increases by 41% for those in the highest exposure categories.

However, the US Environmental Protection Agency and the European Union’s European Food Safety Authority say they have not found a link.

“I worry about any human exposure to carcinogens,” said Dr. Philip Landrigan, a pediatrician at Boston College who has studied glyphosate and its health effects. “But I worry especially when a high proportion of those exposed are children, because children eat more food per pound of body weight per day than adults.”

Glyphosate may also affect children before they’re born, some research says.

A large study in Puerto Rico found an association between mothers exposed to glyphosate in the second trimester and preterm births. Other studies have suggested that the pesticide can interfere with hormones during fetal development.

And some types of glyphosates may be more harmful than others.

Glyphosate with surfactant — which helps it stick to plants — is more toxic in lab-grown human cells than the pesticide alone, according to researchers in the United Kingdom. In cases where people have ingested glyphosate, formulations containing surfactant have resulted in more severe symptoms.

“Surfactants probably enhance the ability of the glyphosate to get into the body,” Landrigan said.

How to reduce exposure to glyphosate

In the mid-1990s, glyphosate and genetically modified crops formed a powerful partnership in the farming industry, driving glyphosate use up 10-fold over the next two decades.

As spraying increased, weeds resistant to glyphosate emerged.

“It’s just like overusing antibiotics,” Landrigan said, likening the shift to antibiotic resistance, when bacteria evolve defenses against drugs meant to kill them.

To fight off hard-to-kill weeds, many farmers now layer in additional herbicides — such as dicamba and 2,4-D — that were far less common two decades ago. The latter was used to produce Agent Orange, an herbicide sprayed by the US military during the Vietnam War.

Landrigan says farmers are also spraying more glyphosate later in the growing season, closer to harvest, which means it may linger on more products.

“It’s much more likely to carry over into the grain,” he said. “There’s no time for the rain, sun and wind to dissipate it.”

Most of the population has been exposed to glyphosate, according to the US Centers for Disease Control and Prevention. That even includes children as young as 3.

Most of that exposure comes from products like whole-wheat bread, whole-grain cereals and crackers, oatmeal, popcorn and legumes. The pesticide has also been identified in drinking water.

The “single most effective” way to reduce exposure to glyphosate is to eat foods with the US Department of Agriculture’s organic seal, according to Landrigan.

Crops with the USDA Organic sticker are not genetically modified, meaning they — like weeds — will die after being sprayed with glyphosate.

Landrigan also recommends buying produce locally and washing it thoroughly before using.

“I don’t think it’s possible in today’s world to avoid these chemicals completely,” he says. “I encourage patients and groups to whom I speak to to do the best they can to minimize their exposure.”

By Michal Ruprecht