Our Perspective: The Truth about Public Health and Safety of GMOs and Herbicides

Our Perspective: The Truth about Public Health and Safety of GMOs and Herbicides

Op-ed in New England Journal of Medicine by authors Philip Landrigan and Charles Benbrook misrepresented extensive regulatory evaluations of glyphosate and other herbicides

By Daniel Goldstein, M.D., Senior Science Fellow & Scientific Affairs Lead, and
Donna Farmer, Ph.D., Product Protection & Nutrition Lead

As a company, our mission is to deliver a broad range of tools to help farmers produce better harvests in a more environmentally sustainable way.  We’re absolutely committed to the safety of our products – whether those products are conventional or GMO seeds or pesticides, and we firmly believe that the only way to ensure safety is through sound science.

Unfortunately, a recent op-ed in the New England Journal of Medicine presented some misinformation about one of our most important products, glyphosate.  The authors of this opinion piece attempt to argue that the recent classification of glyphosate by the International Agency for Research on Cancer (IARC) raises new concerns about glyphosate safety.

Here’s what the authors didn’t mention.

First, the responsibility and authority for evaluating the safety of pesticides lies with regulatory agencies around the world – not with IARC.  Regulatory agencies globally conduct thorough risk assessments based on all available and relevant information about a product.  The conclusions of these risk assessments have been consistent and clear: All labeled uses of glyphosate are safe for human health and the environment.  And there is no credible evidence that glyphosate is a carcinogen.  More information about glyphosate safety is available here.

In contrast, the IARC classification is based on a different approach and selectively used a limited data set.  To be clear: There’s nothing new in the IARC classification.  IARC did not conduct a study, and it did not look at any new data or studies.  Regulatory agencies have reviewed the key studies considered by IARC – and more – to arrive at their more thorough and rigorous conclusions.

To ensure that pesticides continue to meet health and safety standards, regulatory agencies also conduct periodic registration reviews. As part of the registration review process, pesticide manufacturers are required to submit an up-to-date and complete data set to regulatory agencies and to conduct additional studies to fill any data gaps.  The data set on glyphosate includes a battery of 11 different assays for endocrine effects from which EPA concluded that “there was no convincing evidence of potential interaction with the estrogen, androgen or thyroid pathways.” (See EPA’s full weight of evidence report here.)  A number of regulatory agencies, including the U.S. EPA and a European national regulatory authority on behalf of the EU, are currently conducting a reevaluation of glyphosate and are now looking at the IARC monograph as they evaluate glyphosate themselves.

Over the decades that glyphosate has been used as an herbicide, there have been more than 800 studies on glyphosate safety – including many by independent researchers.  This makes glyphosate one of the most extensively studied agricultural products on the market.

The authors of the opinion piece also make claims about the toxicity of formulated glyphosate products.  Here’s what is important to understand.  Most formulated glyphosate products contain three major ingredients: the active ingredient (glyphosate), water, and a soap-like surfactant blend.  The surfactant, which is similar to those used in personal care or home cleaning products, enables the glyphosate to adhere to and penetrate the leaves of a weed.  The surfactant lowers the usage rates of glyphosate on crops by allowing the glyphosate to move through the weeds’ waxy layer, where the glyphosate is able to inhibit an enzyme that is essential for plant growth. When used according to labeled instructions, glyphosate and the surfactants used with glyphosate don’t pose any unreasonable risks to human health.  One of the authors of this blog post, Dr. Donna Farmer, has addressed questions about surfactants in more detail here.

Finally, the authors of the op-ed piece argue in support of mandatory labeling of food products containing ingredients derived from GMOs because of claims about the potential for novel food allergies and the use of crop protection products on GM crops.  It’s important to respond to both claims.  First, as part of the food and feed safety assessment for any new GM crop, the potential trait is fully analyzed for allergenicity.  In the United States, the FDA requires that all ingredients must be listed on the label, and when there is a meaningful difference in the safety, composition or nutrition of the crop from which they were derived, that difference is properly reflected on the label.  The American Medical Association (AMA) has re-affirmed that there is no scientific justification for special labeling of foods containing GM ingredients.

Second, the use of crop protection products is not limited to GM crops.  However, regardless of whether crop protection products will be used on GM or conventional crops, the products undergo detailed regulatory reviews for safety.

We at Monsanto have been clear that we are supportive of a national approach to labeling that benefits consumers by ensuring uniform standards for the safety and labeling of all foods, including those made with ingredients derived from GM crops.  You can read more about Monsanto’s views on labeling in a separate blog post.

When it comes to questions about human health and safety, it’s important to move beyond the rumors and misinformation and read the facts.  Two great places to do that are and  We invite anyone with questions to visit those websites to learn more.