Glyphosate Herbicides and Your Health

Medically Reviewed by Jabeen Begum, MD on June 24, 2024
Written by Kara Mayer Robinson, Shelly Shepard
7 min read

Glyphosate is an herbicide used to kill certain plants and grasses, manage how plants grow, get crops ready for harvest, and ripen fruit. It's called a nonselective herbicide, which means that it kills most plants to which it’s applied. It works by stopping plants from making certain types of proteins that enable them to grow. 

Glyphosate has been used in the U.S. since 1974 and is one of the nation’s most popular herbicides. It’s used on lawns, gardens, forests, and for agriculture.

Glyphosate has many different uses. It's used everywhere from home gardens to big agriculture. Many farmers use it during food production.

It’s often used on:

  • Fruit and vegetable crops
  • Glyphosate-resistant crops such as canola, corn, cotton, soybeans, sugar beets, and wheat
  • Plantings, lawns, greenhouses, aquatic plants, and forest plantings

The biggest users of glyphosate are growers of crops that have been genetically engineered to be resistant to the herbicide — this allows the plant to survive while killing nearby weeds. The crops with the highest use of glyphosate are modified corn, cotton, and soybeans.

Certain glyphosate products (such as Pondmaster) can be used to help control plants in or near ponds and streams.

The herbicide is used in forests to clear land for planting trees as well as weed control, especially for young trees.

Is Roundup the same as glyphosate?

Glyphosate is the declared active ingredient in most versions of Roundup. But Roundup also contains a variety of other ingredients. These ingredients include those designed to help the herbicide stick to plants, be absorbed into the roots, or prevent foaming, as well as dyes.

The Environmental Protection Agency (EPA) in the U.S. says that glyphosate is not likely to cause cancer in humans. But there is concern about the other ingredients in Roundup, as they may be more toxic than glyphosate. These other chemicals are not the “active ingredients” in Roundup, so they are rarely the focus of regulatory health risk assessments. One study found that Roundup was among the most toxic of the herbicides and insecticides tested.

You can be exposed to glyphosate in several ways.

Residential glyphosate exposure

If you use a herbicide containing glyphosate at your home, you could be exposed to it by breathing in particles while spraying it (for example, if it’s windy while using it), or if you accidentally get it on your skin or in your eyes. If you don’t wash your hands or don’t wash them well after using glyphosate, you may be exposed to it when smoking or eating.

Occupational glyphosate exposure

If you have a job in agriculture or landscaping where you regularly use products containing glyphosate, you are at risk of exposure in the same ways as when you use them at home. You should follow the same precautions as those detailed above to reduce your risk of glyphosate exposure.

Studies of farmers found that glyphosate levels in their urine were higher if they did not wear rubber gloves when using the herbicide.

A University of Washington review of numerous studies determined that glyphosate exposure may increase the risk of non-Hodgkin lymphoma by up to 41%. The review included a study with 54,000 people who had jobs applying pesticides.

Environmental glyphosate exposure

Glyphosate binds tightly to soil, and bacteria in the dirt break it down over several months. There is little chance of glyphosate entering groundwater because it binds so tightly to the soil. But it can enter water sources if it’s sprayed directly on the water. 

Glyphosate stays in the air for just a short time when being sprayed on plants, but it does not typically disperse into the air from soil that has been sprayed.

Where you live may affect the degree of your exposure to glyphosate. A recent study of pregnant women in Idaho found that those who lived less than one-third of a mile from fields treated with glyphosate had much higher levels of it in their urine than those who lived farther away.

If you’re exposed, your eyes, skin, nose, and throat may get irritated. If you get it in your eyes, it could lead to mild irritation or a superficial corneal injury. If you swallow it, you may have increased saliva, burns, and pain in your mouth and throat. It can cause nausea, vomiting, and diarrhea.

In some cases, people who intentionally swallowed products with glyphosate have died.

Many farmers use glyphosate products in their fields and orchards. They spray it on crops such as corn and soybeans that are genetically engineered to withstand glyphosate, also known as genetically modified organisms (GMOs). They also spray it on non-GMO crops such as wheat, barley, oats, and beans, to dry out the crops so they can harvest them sooner.

It gets into foods early in the food chain, before raw food is harvested and before it’s processed.

Which foods have glyphosate?

Studies have found glyphosate levels (many of them at legally allowed values) in a variety of foods, including:

  • Honey
  • Fruits and nuts (fruit juice, pears, blackberries, limes, raisins, and walnuts)
  • Grains (breakfast cereals, wheat snacks, bread, wheat seeds, rye, oat, barley, and linseeds)
  • Vegetables, such as yams, potatoes, peas, and dried lentils
  • Meat and fish

Glyphosate in beer

Since barley is the most common grain used to make beer, and studies have detected glyphosate in the grain, it’s not surprising that the herbicide has also been found in beer. One study of 100 samples of beer found glyphosate residue in 92 of the samples.

Glyphosate in oats

In a National Institute of Standards and Technology study of 13 oat-based food samples, the organization detected glyphosate in all of them. But the levels detected were well below the EPA’s tolerance levels.

The study revealed the lowest levels of glyphosate in the organic oat breakfast cereal sample and organic oat flour sample. The highest levels were found in the traditional instant oatmeal samples.

Glyphosate is banned in organic farming, and eating organic can reduce your exposure to glyphosate. One study found that adults and children who started to eat organic had 70% lower levels of glyphosate after 6 days. Glyphosate can still make its way into organically produced foods, but not nearly in the amounts as conventionally grown foods.

Short-term exposure to glyphosate isn’t something you need to worry much about. But its long-term risk may be a concern. Scientists are divided on how much risk is involved. Reports show conflicting results. And keep in mind that most studies involve animals, not people:

Cancer. Some studies suggest glyphosate may be linked to cancer. Others suggest there’s no link. The International Agency for Research on Cancer categorizes glyphosate as a probable carcinogen for humans. The EPA says that glyphosate does not pose a risk to humans as long as it is used according to directions. They also stated that it is unlikely that it causes cancer in humans. A 2023 study by The University of California, Berkeley, found that glyphosate is a probable human carcinogen.

Liver and kidney damage. Glyphosate may affect your kidney and liver. Studies of humans have found possible links between glyphosate and non-alcoholic fatty liver disease, metabolic syndrome, cirrhosis, and chronic kidney disease.

Endocrine and reproductive issues. The EPA says that there is no evidence that glyphosate interferes with the endocrine system or hormones in humans. A 2024 study linked glyphosate levels to infertility in men.

Digestive issues. According to a 2020 study, a majority of gut bacteria may be susceptible to glyphosate, which could affect the makeup of the human gut microbiome.

You can limit your risk of glyphosate exposure in several ways:

  • Always wash your hands carefully after using glyphosate or if you’ve touched plants that have been sprayed in the past 24 hours.
  • Wear protective clothes, such as long-sleeved shirts and long pants whenever using glyphosate, whether you’re a farmer or a gardener.
  • Don’t let the spray blow onto your skin (avoid spraying on a windy day).
  • Never eat, drink, or smoke while using glyphosate.
  • Don’t walk around barefoot less than 24 hours after an area has been sprayed.
  • Buy organic foods.
  • Wash fruits and vegetables thoroughly.
  • Keep children away from glyphosate products and areas that have been sprayed.
  • Keep pets away from treated areas according to the product instructions.

While the EPA has stated that glyphosate is unlikely to cause cancer and other negative health effects in humans, some studies dispute that. With the variety of contradictory information available, it’s a good idea to be aware of the potential links between glyphosate and health issues and take steps to limit your exposure.