What Is Glyphosate?

An Herbicide Also Known as Roundup

Glyphosate is a herbicide that’s used to control weeds and grasses. It’s the active ingredient in many herbicide products, including the popular Roundup. Glyphosate has been registered as a pesticide in the U.S since 1974, and It’s also commonly used in many other countries around the world. Herbicides containing glyphosate are also referred to as weed killers.

Aerial view of rtactor spraying wheat field
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Composition

Glyphosate is a phosphonic acid derived from a reaction between the methyl group of methylphosphonic acid with the amino group of glycine. It is the only herbicide that attacks the enzyme 5-enolpyruvyl-3-shikimate phosphate synthase (EPSPS). 

How It Works

Glyphosate is a broad-spectrum herbicide. This means that it can’t be used to kill specific weeds or plants. Instead, it kills most broadleaf plants in the area it is used.

Glyphosate works by inhibiting the action of a plant enzyme that plays a role in the synthesis of three amino acids named phenylalanine, tyrosine, and tryptophan.

Glyphosate is absorbed into plants primarily through its leaves, and only tiny amounts of it are absorbed into the roots. Consequently, glyphosate is actually only effective at killing growing weeds and grass. It cannot stop seeds from germinating in the first place.

Once it is absorbed into the plant structure, glyphosate spreads all around the plant—to its roots and leaves—and prevents it from making proteins that are necessary for its growth. This is what ends up killing the plants.

Forms

You can find herbicide products containing glyphosate in liquid, concentrate, and solid forms. Glyphosate can be applied to plants and weeds through injection systems, sponge bars, aerial sprays, broadcast sprayers, shielded sprayers, wiper applicators, and controlled droplet applicators.

Uses

The primary uses for glyphosate are as an herbicide and as a crop desiccant.

Herbicide

Glyphosate is one of the most commonly used herbicides. It’s used for different scales of agriculture— in households and industrial farms, and many places in between.

Its use as a herbicide isn’t limited to just agriculture though. It’s also utilized in public spaces like parks and playgrounds to prevent the growth of weeds and other unwanted plants.

Crop Desiccant

Glyphosate is sometimes used as a crop desiccant. Desiccants are substances that are used to maintain states of dryness and dehydration in environments they are present in.

Farmers use glyphosate to dry crops like beans, wheat, and oats right before harvesting them. They do this to speed up the harvest process and improve the harvest yield as a whole.

In reality, however, glyphosate is not a true desiccant. It just functions like one for crops. It kills the plants so that the food portions of them dry out faster and more uniformly than they ordinarily would.

Risks and Hazards

Because of how widespread its usage is, glyphosate is continuously being studied for possible effects of long-term exposure to it by humans, animals, and insects.

The U.S Environmental Protection Agency (EPA) has conducted extensive investigations into glyphosate and its effects on human health, the environment, and the safety of foods. After reviewing available data on glyphosate, here’s what the agency determined.

Human Health

EPA studies have concluded this about the effects of glyphosate on human health:

  • When used according to directions on herbicide product labels glyphosate does not pose any risk to adults. 
  • There’s also no reason to believe that children are more sensitive to the chemical, or that it poses any special risk to them—whether they’re exposed to it during pregnancy or after they’re born.
  • There’s no risk to children that eat foods with residues of glyphosate, neither is there any concern about children playing in residential environments where glyphosate has been used.
  • There’s no indication that glyphosate disrupts the endocrine system. 
  • Glyphosate is not likely to cause cancer in humans.

Other organizations that support the assertion made by the EPA that glyphosate does not cause cancer include the European Chemicals Agency, Canadian Pest Management Regulatory Agency, European Food Safety Authority, the Joint Food and Agriculture Organization/World Health Organization (FAO/WHO), and the German Federal Institute for Occupational Safety and Health.

It is important to note, though, that the International Agency on the Research for Cancer (IARC) deems glyphosate to be “probably carcinogenic to humans.”

Ecological Health

EPA studies have concluded this about the effects of glyphosate on the environment:

  • Glyphosate poses a potential risk to birds, and plants on land and in water. 
  • It is of low toxicity to honey bees.

Food Safety

Glyphosate is widely used and so trace amounts of it may be detected in fresh fruits, cereals, vegetables, and many other food products. These residues should not concern you as they pose no risk.

As long as foods and food products comply with the limits set by the EPA, they’re safe for consumption. These limits are set by the EPA and specify how much pesticide residue can be left on food products.

Food products that are discovered to have pesticide residues above the specified limits can be seized by the government. Nevertheless, the fact that you can personally detect pesticide residue on food or food products does not necessarily mean that it's above safe levels.

Legality

Glyphosate herbicides are legal in the U.S and most other countries around the world. Some countries hover, have either banned it completely or set out specific restrictions regarding its use:

  • In 2014, the legislature of the Netherlands prohibited glyphosate from being sold to consumers to use at home.
  • As of June 30th, 2021 the sale and use of glyphosate herbicides will be banned in Vietnam.
  • The German government also announced in 2019 that the use of glyphosate will be prohibited startng from the end of the year 2023. 

A Word From Verywell

Many health and environmental agencies around the world have determined that glyphosate is safe for use as long as labeling instructions are followed. It is not necessary for you to stop using glyphosate herbicides, but it may be advisable to limit unnecessary exposure to it. Nevertheless, investigations will likely continue as to its safety.

 

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Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Tarazona J, Court-Marques D, Tiramani M et al. Glyphosate toxicity and carcinogenicity: A review of the scientific basis of the European Union assessment and its differences with IARCArch Toxicol. 2017;91(8):2723-2743. doi:10.1007/s00204-017-1962-5

  2. Government Printing Office. 40 CFR 180.364 - Glyphosate; tolerances for residues. July 1, 2010.

Additional Reading
  • Environmental Protection Agency (EPA). Glyphosate.