Frequently Asked Questions about Glyphosate and Roundup Brand Agricultural Herbicides

Below find answers to common questions about glyphosate and Roundup® brand herbicides. Our goal is to simplify complicated study findings and demystify the science behind glyphosate-based herbicides. Additional links and resources are provided for those looking for more detailed scientific information.

1. Is glyphosate safe for humans and the environment?
Glyphosate-based herbicides are supported by one of the most extensive worldwide human health, safety and environmental databases ever compiled for a pesticide product. Comprehensive toxicological studies repeated over the last 40 years have time and again demonstrated that glyphosate poses no unreasonable risk to people, the environment, or pets when used as directed on the label. >>Learn more about the safety of glyphosate.

2. Are “Roundup” and glyphosate the same?
Glyphosate is the major active ingredient in Roundup® brand herbicides. In addition to glyphosate, Roundup brand herbicides contain water and a soap-like surfactant that helps enable the active ingredient to enter plant leaves. Some Roundup brand herbicides do contain additional active ingredients. There are also many glyphosate products carrying other brand names, from both Monsanto and other manufacturers.>> Learn more about Roundup brand agricultural herbicides.

3. Is Monsanto the sole manufacturer of glyphosate-based herbicides?
No. Monsanto discovered and patented the original molecule for glyphosate in 1969 and held the U.S. patent until 2000. Today many other companies have registered their own glyphosate-based herbicide products for use in modern agriculture as well as lawn and garden, industrial, turf and ornamental.

4. Do governments regulate the use of glyphosate-based products, such as Roundup brand herbicides?
Yes. Regulatory agencies around the world review safety data for glyphosate and other pesticides before approving their use. In the U.S., the Environmental Protection Agency is responsible for regulating all pesticide ingredients. As part of its review, the EPA requires developers to submit data on, among other things, toxicity, ecotoxicity and environmental fate. The EPA also solicits public comments and conducts periodic reviews of pesticides on the market to ensure they meet current regulatory standards. >> Learn more about the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA).

5. Why should I trust Monsanto and other companies when they talk about the safety of their products?
Herbicide manufacturers are required by law to conduct a variety of studies and report new findings of adverse effects when they become aware of them. Government regulators around the world carefully review these studies. Data for these studies are produced under good laboratory practice requirements established by governmental regulations, which mandate study documentation, measures of study quality and allow the U.S. EPA to conduct audits and review the raw data. If a company does not conduct reporting required by law, they face potential penalties from the regulatory authorities. >> Learn more about the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA).

6. Why do some studies contradict glyphosate’s widely established safety profile?
If Monsanto learns of a study that questions the safety of glyphosate, our product safety teams and scientists review the study carefully. This is part of the scientific process—questioning, testing, reviewing and sharing information about scientific results. After our internal review of the study, we share our point of view with the scientific community.

Studies that contradict the safety profile of glyphosate have not met most sound, scientific criteria for study development and protocols. For example, some are not peer reviewed, and others may not reflect “real world” conditions of exposure and dosage. However, many other studies, including those by regulatory authorities around the world, have been shared and are supported by good science and stand up to the rigor of the scientific review process. Learn more from government regulatory authority reviews on glyphosate safety.

7. Why is the state of California proposing to add glyphosate to the Proposition 65 list?
On Sept. 4, 2015, the California Office of Environmental Health Hazard Assessment (OEHHA) announced its intention to add glyphosate to the state’s Proposition 65 list. The sole basis of OEHHA’s intention to add glyphosate to the Prop 65 list was the classification of glyphosate in Category 2A earlier this year by the International Agency for Research on Cancer (IARC). OEHHA interprets Prop 65 to allow it simply to accept the IARC classification without further scrutiny or review. OEHHA does not evaluate the weight or quality of the evidence considered by IARC. Monsanto strongly disagrees with the IARC classification, which is in opposition to the overwhelming scientific consensus of regulatory agencies around the world.

8. Does glyphosate cause cancer?
Comprehensive long-term toxicological studies repeated over the last 40 years have time and again demonstrated that glyphosate is unlikely to pose a cancer risk in humans. In the US EPA groups glyphosate in the lowest category E, indicating evidence of noncarcinogenicity for humans. >> Learn more about the science in the Regulatory Toxicology and Pharmacology Journal.

9. Does glyphosate accumulate in milk from either humans or farm animals?
Glyphosate is water soluble, not fat soluble. These studies show that there is minimal retention of glyphosate in tissues in animals and humans; and if exposure were to occur, it is rapidly eliminated from the body. Glyphosate works by blocking a metabolic pathway that’s essential for a plant’s growth. This pathway is present in plants, but does not exist in humans and animals. >> Learn more about the science on our blog and from the Genetic Literacy Project.

10. Does glyphosate cause reproductive problems or birth defects?
Regulatory authorities and experts around the world agree that glyphosate does not cause adverse reproductive effects in adults or birth defects in offspring of these adults exposed to glyphosate. Likewise, an international panel of renowned toxicologists concluded that the use of the original Roundup® brand herbicide according to label instructions “does not result in adverse effects on development, reproduction or endocrine systems in humans and other mammals.” >> Learn more about the science.

11. Does glyphosate cause autism?
No, there is no evidence to support the alleged connection between Autism Spectrum Disorder (ASD) and pesticide exposure. Simply because there is an increased use in glyphosate-based herbicides and an increased diagnosis of autism during the same time frame does not create a cause-and-effect relationship. >> Learn more about non-causal correlations and causation.

12. Is glyphosate in urine a cause for concern?
There are no health concerns associated with trace amounts of glyphosate detected in urine. Urine is an excretion route for many chemicals, including glyphosate. Levels of glyphosate that have been detected in human urine in the general population, and even among farmers using glyphosate, correspond to intakes that are well below any allowable daily intake set by regulatory agency.. >> Learn more in an article from a well-respected physician and professor at Harvard Medical School; a farm family exposure study; and a an answer to a similar question on

13. Does glyphosate cause chronic kidney disease?
Exposure to glyphosate-based products is not associated with kidney disorders or chronic kidney disease (CKD) according to multiple epidemiological and animal studies. >> Learn more at

14. Does glyphosate cause Parkinson’s disease?
No increased risk of Parkinson’s disease has been found in association with glyphosate. >> Learn more about this alleged association.

15. Does glyphosate cause Celiac disease?
No. Celiac disease is an immune disorder caused by an adverse reaction to gluten, a protein naturally present in wheat flour. There is no scientific evidence that glyphosate causes or exacerbates celiac disease. >> Learn more about the science.

16. Does glyphosate cause non-Hodgkin’s lymphoma?
There is no scientific evidence that links glyphosate to non-Hodgkin’s lymphoma (NHL) or other forms of cancer. >> Learn more about the science in the Regulatory Toxicology and Pharmacology Journal.

17. Does glyphosate disrupt endocrine systems or act as a hormone?
Glyphosate was recently examined to determine whether it can disrupt endocrine systems or act as a hormone as part of EPA’s Endocrine Disruptor Screening Program. The results of this assessment demonstrate that glyphosate did not have endocrine activity. Additionally, a recent comprehensive review of the available literature to assess the developmental and reproductive safety of glyphosate concluded “the literature shows no solid evidence linking glyphosate exposure to adverse developmental or reproductive effects at environmentally realistic exposure concentrations.” >> Learn more about Developmental outcomes in humans and animals after glyphosate exposure.

18. Does glyphosate or its formulated product kill human cells?
From time to time researchers will publish data claiming that formulated herbicides containing glyphosate cause unexpected toxicity to human cells. These observations are the result of the surfactants used in formulated herbicides interacting with unprotected human cells in petri dishes. Surfactants, are soapy-like substances, that are used to help the herbicide spread on leaves and enter the plant. Surfactants found in household and personal care products have been shown to have similar effects on unprotected cells in petri dishes. >> Learn more about the science and

19. Does glyphosate alter human DNA?
No, several toxicology reviews of glyphosate have consistently concluded that glyphosate is not genotoxic. On the basis of the studies considered scientifically valid and suitable for risk assessment, public health officials agree that glyphosate is not genotoxic to humans and therefore cannot alter our DNA. In fact, the U.S. Environmental Protection Agency reviewed extensive toxicological and environmental data and classified glyphosate in its most favorable acute toxicity category, “practically non-toxic.”

20. Is there a harmful effect of glyphosate on honey bees?
Bees play a vital role in our agricultural system, and we share concerns about bee health. Decades of toxicity studies with glyphosate and Roundup® brand herbicides demonstrate no acute or chronic adverse effects to honey bees when using good agricultural practices. Honey bee adults and larvae are not affected by glyphosate or glyphosate-based herbicides under normal field conditions. >> Learn more about a glyphosate and honey bee study and how Monsanto is invested in improving agriculture and honey bee health.

21. Has the monarch butterfly been impacted by glyphosate?
Monarch butterfly populations have declined in recent years. Many scientists studying monarchs think a number of factors are contributing to the decline, including logging, weather and loss of habitat. The declining availability of milkweed plants for butterfly habitat is one contributing factor. We’re collaborating with experts from universities, nonprofits and government agencies to help restore lost monarch habitats. >> Learn more about our work to protect the monarch butterfly.

22. Does glyphosate harm aquatic wildlife?
Glyphosate has very low toxicity to aquatic wildlife. Read the labels carefully to ensure a product is labeled for use in streams, lakes and other aquatic habitats. >> Learn more about the science.

23. Does glyphosate cause wildlife reproductive problems?
No. Environmental exposures to glyphosate-based formulations do not cause adverse effects on wildlife reproduction when used according to label directions. >> Learn more about the science.

24. Does glyphosate cause “super weeds”?
Weed control has always been a challenge for agriculture. Some weeds have developed a resistance to some herbicides. On the farm, the principles of good weed management can limit the emergence of resistance, and that’s why multiple modes of action are often necessary today. >> Learn more about weed control technology.

25. Are microorganisms in the soil harmed by glyphosate?
There is no indication from environmental studies that glyphosate harms soil microbial communities. Actually glyphosate is biologically degraded over time by soil microorganisms into products that are naturally occurring, including carbon dioxide and phosphate. Remember that microbes are ubiquitous and each type responds to changes in the environment, including temperature and rainfall. >> Learn more about the science.

26. What protections has Monsanto created through the Endangered Species Initiative?
We implemented a stewardship program called the Glyphosate Endangered Species Initiative. This web-based tool helps growers identify areas where threatened or endangered plant species may exist near agriculture, and prescribes best management practices that growers must implement with certain use patterns and application rates in these identified areas to minimize risks to these protected plant species. >> Visit to learn about this program.