The Truth about Glyphosate: Genuine Concerns and Sobering Realities
Miles Pollard /
The use of the agricultural input glyphosate may be one of the most hotly contested issues within public health right now. For some, glyphosate is proof that modern agriculture is poison. For others, it is an example of anti-science panic.
Both reactions avoid the hard truth: glyphosate is a critical agricultural input with contested cancer literature, collapsing public trust, and a set of policy tradeoffs that are too often ignored.
The large scale skepticism of glyphosate safety started in 2015 when the WHO’s International Agency for Research on Cancer classified glyphosate as probably carcinogenic (Group 2A), based on “limited” evidence in humans alongside animal and mechanistic evidence.
However, this legitimate concern is based more on potential theoretical hazards rather than an assessment of real-world exposure levels. Regulating agencies ask a different question: whether a substance poses an unacceptable risk when used as labeled.
In the U.S., the Environmental Protection Agency has maintained that glyphosate is “not likely to be carcinogenic to humans.” However, it has since withdrawn its 2020 interim decision following U.S. Court of Appeals Ninth Circuit litigation and is now revisiting parts of its analysis.
Across the pond, the European Food Safety Authority said in 2023 that it found no “critical areas of concern,” and the European Commission renewed glyphosate’s approval through 2033. Similarly, the European Chemicals Agency concluded that the available evidence did not justify classifying glyphosate as carcinogenic, mutagenic, or reprotoxic.
As for the studies used to justify such decisions, one of the strongest prospective cohorts in the debate, the Agricultural Health Study. The study followed more than 54,000 licensed pesticide applicators in North Carolina and Iowa. An analysis from 2018 found no overall association between glyphosate and non-Hodgkin lymphoma but did report some evidence of increased acute myeloid leukemia risk in the highest exposure groups.
Later, a pooled AGRICOH analysis from 2019 covering more than 316,000 farmers and agricultural workers in France, Norway, and the U.S. similarly found no association, though it reported a borderline elevation for diffuse large B-cell lymphoma among long-term users of glyphosate.
When looking at meta-analyses, which are literature reviews of several studies to ascertain patterns, the data is still contested. In 2019, a meta-analysis of the Agricultural Health Study’s highest exposure cohort found a 41% increased relative risk of non-Hodgkin lymphoma.
However, in 2020 another meta-analysis and its follow up in 2021 came to more restrained conclusions, cautioning readers about the literature’s publication bias but confirming that diffuse large B-cell lymphoma cannot be ruled out.
An honest summary of the literature neither exonerates nor condemns glyphosate. High exposure individuals, like farmers with specific lymphoma subtypes, are worth monitoring.
This scientific uncertainty should give policymakers pause. Glyphosate has become the most used pesticide (specifically as an herbicide) in the US, sprayed on over 100 crops.
U.S. glyphosate usage has risen from less than 5,000 to over 80,000 metric tons per year between 1987 and 2007. This more than 15-fold increase was accompanied by the deployment of glyphosate-tolerant crops and reduced tillage practices.
Most prevalent among these was Roundup by Monsanto, which was purchased by Bayer in 2018. Whatever one thinks of glyphosate and Bayer’s acquisition of Monsanto, banning such a prevalent pesticide may create regrettable substitutions.
In fact, Bayer actually stopped selling glyphosate-based Roundup for the U.S. residential market in 2023, citing ongoing litigation issues rather than safety concerns. As of February, 2026 the company has paid $11 billion for civil suits. Some Roundup formulations were replaced with diquat dibromide, which is banned in the EU due to its higher toxicity.
According to the U.S. Agency for Toxic Substances and Disease Registry, glyphosate’s chronic intake threshold is 1 milligram per kilogram of body weight per day while the European Food Safety Administration sets their threshold at 0.5 milligram per kilogram of body weight per day.
Comparatively, diquat dibromide’s threshold is between .002 and .005 milligram per kilogram of body weight per day, which is 100-500 times lower than glyphosate. However, it is worth noting that actual formulations containing diquat may be substantially lower than glyphosate, mitigating some risk.
Evidence aside, the decision to restrict glyphosate usage also depends on safe, efficient, and effective alternatives. One important insight to consider is how glyphosate itself replaced more dangerous pesticides used prior to its introduction.
Agent Orange, the infamous defoliant used during the Vietnam War, contained one of glyphosate’s predecessors, 2,4,5-T. This compound was unfortunately contaminated with dioxin, a potent neurotoxin, due to inconsistent chemical treating. Dioxin’s threshold is .0000000007 milligram per kilogram of body weight per day, which is around a billion times more toxic than glyphosate.
This formulation has thankfully been banned since the mid-1980s, accompanying glyphosate’s rise in popularity. Glyphosate was detected in about 81% of Americans, with an average concentration of 0.000411 mg/liter of urine, which is thousands of times lower than the chronic intake threshold.
This is not to dismiss concerns over glyphosate toxicity, as many have raised questions about glyphosate’s effect on the gut microbiome. Others also have germane concerns about glyphosate mixed with other “enhancing” chemicals that increase toxicity.
Neither extreme should dominate the debate. Advocating for banning or restricting a well-used pesticide may lead to alternative pesticide regimes with more chemical alternatives, more over-applications, more tillage and soil erosion, or higher costs shifted onto families.
Glyphosate’s path forward demands nuanced, evidence-based policy including rigorous ongoing monitoring (especially for high-exposure populations), innovation in alternatives, transparent risk communication, and balanced regulation that takes these genuine concerns seriously and analyzes the realities of tradeoffs soberly.