The March Against Monsanto: How a Facebook Page Became a Global Movement, and What It Changed

On May 25, 2013, people gathered in cities around the world for the first “March Against Monsanto.” The movement began only three months earlier with a Facebook page created by Tami Canal, a mother in Utah, who hoped a few thousand people might join. Organizers later claimed that about two million people marched in 436 cities across 52 countries, figures that could not be independently verified but reflected a striking level of mobilization. Protesters demanded labeling of genetically engineered foods and opposed Monsanto’s seeds, pesticides, patents, and political influence.

In interviews at the time, organizers framed the movement around both opposing Monsanto and promoting organic and local food. More than a decade later, the landscape has changed: the Monsanto name no longer exists, federal GMO disclosure took effect, and Roundup litigation reached the Supreme Court. This article looks at the movement’s origins, what it achieved, why debates over GM foods became so polarized, and what lessons it offers.

What was the March Against Monsanto? It was a global protest movement that began in 2013 from a single Facebook post and grew into coordinated marches in hundreds of cities. Protesters opposed GMOs, pesticides, and corporate control of food, demanding labeling and tighter regulation. Scientists noted that approved GM foods are safe to eat, but many of the movement’s concerns about herbicides and corporate power were legitimate.

How Did the March Against Monsanto Start?

The movement began in early 2013 when a single Facebook post calling for a protest against Monsanto went viral, quickly growing into coordinated marches in hundreds of cities worldwide. The Associated Press, as published by the Christian Science Monitor, reported that the movement began when founder Tami Canal created a Facebook page on February 28, 2013, calling for a rally against Monsanto’s practices, and that organizers said protests were held in 52 countries and 436 cities, including Los Angeles, where demonstrators carried signs calling for labeling of genetically modified foods. PBS SoCal noted that Canal had hoped for 3,000 participants and that the two million estimate came from organizers, cautioning readers that the numbers could not be independently confirmed while observing that turnout was nonetheless large. A second global march followed in October 2013, and annual marches continued for several years.

The timing was not accidental. In 2012, California voters narrowly rejected Proposition 37, a ballot measure to require GMO labeling, after an expensive opposition campaign funded largely by agricultural and food companies. Activists channeled frustration into grassroots organizing, aided by social media, which allowed rapid coordination across countries without a central organization.

What Did the March Against Monsanto Want?

Protesters demanded mandatory GMO labeling, tighter pesticide regulation, and limits on corporate control of the food supply, driven by distrust of Monsanto and concerns about health and the environment. March Against Monsanto brought together people with varied concerns: food safety and the long-term health effects of genetically engineered crops; pesticide use, particularly glyphosate; corporate control of seeds through patents; the economic situation of farmers; environmental impacts; and the influence of agribusiness on government. The central policy demand in the United States was mandatory labeling of genetically engineered foods. Grist noted that the first march came just two days after the U.S. Senate rejected an amendment by Senator Bernie Sanders that would have affirmed states’ rights to require GMO labels.

Demand	What happened
Mandatory GMO labeling	Vermont passed a law in 2014; Congress passed a national standard in 2016; federal bioengineered disclosure took effect in 2022, with QR code options criticized by advocates
Accountability for glyphosate harms	Thousands of Roundup lawsuits and large settlements; Supreme Court limited failure-to-warn claims in 2026
Limiting corporate seed control	Industry consolidated further; four firms now dominate seeds and agrochemicals
Support for organic and local food	Organic sales grew to record levels over the following decade

The labeling story is told in our article on the fight over GMO labels, and the litigation story in our article on glyphosate and the 2026 Supreme Court ruling.

The Gap Between Scientists and the Public

The movement unfolded alongside a large gap between scientific and public opinion. A 2015 Pew Research Center survey found that 88 percent of scientists affiliated with the American Association for the Advancement of Science said it is generally safe to eat GM foods, compared with 37 percent of the U.S. public, a 51-point gap that was the largest among 13 science issues studied. Two-thirds of the public said scientists do not have a clear understanding of the health effects of GM crops.

Psychology research has explored why opposition can be so strong. A 2016 study in Perspectives on Psychological Science by Sydney Scott, Yoel Inbar, and Paul Rozin found that 64 percent of a representative U.S. sample opposed genetic modification of food and that 71 percent of opponents, or 45 percent of the whole sample, were “absolutely” opposed, saying GM should be prohibited regardless of risks and benefits, a moral stance that evidence about safety is unlikely to change. A 2019 study in Nature Human Behaviour by Philip Fernbach and colleagues found that as opposition to GM foods became more extreme, objective scientific knowledge decreased while self-assessed understanding increased.

Criticisms of the Movement

The movement drew criticism from scientists, farmers, and journalists. Critics argued that some March Against Monsanto social media pages spread misinformation and conspiracy theories, including false claims about vaccines and exaggerated or fabricated health claims about GM foods, which undermined legitimate concerns. Some scientists who studied or publicly supported biotechnology reported harassment. Supporters of GM crops argued that the movement ignored scientific consensus on food safety and overlooked benefits such as reduced insecticide use with Bt crops. Within the movement, some participants emphasized evidence-based concerns about pesticides, corporate power, and transparency, while others promoted more sweeping claims. This diversity made the movement broad but also exposed it to criticism.

Which of the Movement’s Concerns Were Legitimate?

While the food-safety fears about GMOs were not supported by evidence, the movement’s concerns about heavy herbicide use, corporate concentration of seeds, and the right to know what is in food were legitimate. Separating exaggerated claims from legitimate questions is important. Evidence-based concerns highlighted by the movement included increased herbicide use with herbicide-tolerant crops and the spread of resistant weeds; insect resistance to Bt traits; consolidation of the seed and agrochemical industries; the influence of industry funding on research and regulation; and consumers’ desire for transparency. These issues are discussed by scientists, economists, and regulators, not only activists. Questions about food safety of approved GM crops, by contrast, have been examined extensively, and major scientific bodies have concluded that approved GM foods are as safe to eat as their conventional counterparts.

Are GMO Foods Safe to Eat?

Major scientific bodies have concluded that approved GM foods are as safe to eat as conventional foods, so the movement’s health claims about eating GMOs were not borne out by the research. A 2014 review in Critical Reviews in Biotechnology by Alessandro Nicolia and colleagues examined about 1,800 scientific records published over a decade on genetically engineered crop safety, covering environmental interactions, human and animal food safety, and traceability, and concluded that research had not detected significant hazards directly connected with the use of GE crops, while noting that the debate remained intense. The U.S. National Academies of Sciences, Engineering, and Medicine reached similar conclusions about food safety in a 2016 report, while emphasizing that effects on agriculture and the environment vary by crop, trait, and context.

Why does opposition persist despite such conclusions? A 2015 paper in Trends in Plant Science by Stefaan Blancke and colleagues argued that GMO opposition draws on intuitions, such as beliefs that organisms have an essence that should not be altered, feelings of disgust, and a tendency to see interference with nature as dangerous, which make anti-GMO messages compelling regardless of evidence. Understanding these intuitions helps explain why the March Against Monsanto resonated widely and why scientific information alone has not resolved the debate.

What Happened to the Movement After Monsanto Was Sold?

After Bayer bought Monsanto in 2018 and retired the Monsanto name, the marches faded, but concerns about glyphosate, corporate power, and food transparency continued through other campaigns and litigation. When Bayer acquired Monsanto in 2018, it retired the Monsanto name, removing the movement’s symbolic target. Activism shifted toward Bayer, glyphosate litigation, pesticide regulation, and newer technologies such as gene editing. Annual marches became smaller, while other organizations continued campaigns on labeling, pesticides, and regenerative and organic agriculture. The movement’s legacy includes heightened public awareness of food system issues, the growth of non-GMO and organic markets, and a model of social-media-driven global protest.

Social Media and Food Movements

The March Against Monsanto was one of the first global food movements organized primarily through social media. A single Facebook page allowed volunteers in hundreds of cities to coordinate events, share materials, and spread messages without a formal organization or budget. The same tools that enabled rapid mobilization also allowed misinformation to spread quickly, since posts could circulate widely without fact-checking. Later food and health movements have used similar strategies, and researchers studying online communication have found that emotionally charged and moralized messages tend to spread more widely, which helps explain both the movement’s reach and the criticism it attracted.

Organic and Non-GMO Markets

One of the clearest legacies of anti-GMO activism has been in the marketplace. Sales of organic food and products verified as non-GMO grew substantially in the decade after 2013, and many food companies reformulated products to avoid genetically engineered ingredients or sought non-GMO certification. Retailers expanded organic private-label lines. These market shifts gave consumers more choice, though they also raised questions about whether non-GMO labels on products with no GMO counterparts, such as salt or water, misled consumers. Our article on the USDA Organic seal and non-GMO labels explains what these labels mean.

Farmers’ Perspectives

Farmers often viewed the March Against Monsanto differently from urban protesters. Many conventional farmers adopted genetically engineered seeds because they simplified weed and insect control, reduced some pesticide use, and improved yields, and some felt their practices were unfairly portrayed. Other farmers, including organic producers and those concerned about seed costs and corporate power, shared some of the movement’s concerns. Debates over GMOs often highlighted divides between consumers and producers, and efforts to bridge them have emphasized dialogue about specific practices rather than broad generalizations.

Key Facts at a Glance

The March Against Monsanto began with a Facebook page created February 28, 2013, and organizers claimed the first march on May 25, 2013, drew about two million people in 436 cities across 52 countries. A 2015 Pew survey found 88 percent of scientists versus 37 percent of the public considered GM foods generally safe to eat. A 2016 study found 45 percent of Americans were absolutely opposed to GM food regardless of risks and benefits. A 2014 review of about 1,800 studies found no significant hazards directly connected with GE crops. Bayer acquired Monsanto in 2018 and retired its name, and federal bioengineered food disclosure took effect in 2022.

Patents and Seed Saving

A central grievance of the movement concerned seed patents. Genetically engineered seeds are protected by patents, and seed purchase agreements typically prohibit farmers from saving and replanting seed. In Bowman v. Monsanto (2013), the U.S. Supreme Court unanimously ruled that a farmer who planted second-generation patented soybeans bought from a grain elevator infringed Monsanto’s patent. Critics saw such cases as evidence of corporate control over farmers; the company argued patents protect investments in research. Seed saving is a traditional practice in many parts of the world, and conflicts over seed rights remain prominent in international debates, although many farmers in industrialized countries have purchased hybrid seed annually for decades regardless of genetic engineering.

Global Dimensions

The march drew participants in Europe, Latin America, Asia, Africa, and Australia, reflecting different national concerns. In Europe, where GM crop cultivation is limited and labeling has long been mandatory, protests focused on keeping GM crops out and opposing pesticides. In Argentina and Brazil, large-scale GM soybean cultivation and associated herbicide spraying raised concerns among rural communities. In India, debates centered on Bt cotton, seed prices, and farmer welfare. The global reach showed how Monsanto had become a symbol for broader concerns about industrial agriculture and globalization, even where its direct presence was limited.

Common Myths

“Two million people definitely marched.” This was an organizer estimate that was not independently verified.

“Approved GM foods have been shown to be harmful.” Major scientific reviews have not found significant hazards from approved GM foods, though debates continue over environmental and economic effects.

“The movement achieved nothing.” It contributed to labeling debates, market changes, and public awareness of food system issues.

“All GMO critics reject science.” Many critics focus on evidence-based concerns about pesticides, resistance, and corporate concentration.

Key Terms

GMO: A genetically modified organism, typically one altered using genetic engineering.

Bioengineered food: The U.S. regulatory term for foods containing detectable genetic material modified through certain lab techniques.

Proposition 37: A 2012 California ballot measure to require GMO labeling, narrowly defeated.

Seed patent: Intellectual property protection for engineered seed traits.

Scientific consensus: The collective judgment of the scientific community based on evidence.

The Bottom Line

The March Against Monsanto grew from a single Facebook page into a global protest movement that channeled concerns about genetically engineered foods, pesticides, seed patents, and corporate power. Its organizer-reported turnout figures were unverified, but its reach was substantial. The movement helped push labeling onto the policy agenda and contributed to the growth of organic and non-GMO markets, though federal labeling fell short of what advocates sought. It also illustrated a deep gap between public and scientific opinion on GM food safety, rooted partly in moral intuitions and distrust of corporations. Separating evidence-based concerns about pesticides, resistance, and market concentration from unsupported claims remains the key to productive debate.

Further Reading

Contemporary news coverage from 2013 describes the first marches. Pew Research Center surveys track public and scientific opinion on GM foods. Peer-reviewed reviews of GE crop safety and psychological research on GMO attitudes provide context for understanding the debate. Other articles on this site cover GMO labeling, glyphosate litigation, and seed industry concentration.

Lessons for Future Movements

The March Against Monsanto offers lessons for anyone organizing around food and health. Grassroots mobilization through social media can build momentum quickly, but credibility depends on accuracy, and misinformation can undermine legitimate goals. Focusing on specific, evidence-based demands, such as transparency, pesticide reduction, or fair competition, can attract broader support than sweeping claims. Engaging farmers, scientists, and policymakers rather than treating them as opponents can lead to more durable change. And sustained institutional work, through legislation, litigation, and market development, often matters more than a single day of protest.

How Food Activism Has Evolved

Since the March Against Monsanto, food activism has diversified. Campaigns now address regenerative agriculture, soil health, ultra-processed foods, synthetic food dyes, pesticide residues, and food access. Some activists have shifted from opposing genetic engineering broadly to scrutinizing specific traits, uses, and business practices, while others continue opposing GMOs entirely. Gene editing has opened new debates about whether edited crops should be regulated or labeled like earlier GMOs. Federal attention to food additives and chemicals in 2025 and 2026 brought some long-standing activist concerns into mainstream policy, showing how ideas once seen as fringe can influence government agendas.

Questions Readers Can Ask About Food Claims

When encountering claims about GMOs or food companies, consider: Is the claim about safety to eat, environmental effects, economics, or corporate behavior? What evidence supports it, and is it peer-reviewed? Does the source acknowledge uncertainty and opposing evidence? Who benefits from the message? These questions help readers navigate a debate in which both industry and activist messaging can be selective.

Why Monsanto Became the Symbol

Monsanto became the focus of the movement for several reasons. It was the leading developer of genetically engineered seed traits and the maker of Roundup, the world’s best-selling herbicide. Its history included manufacturing PCBs and Agent Orange, discussed in our article on Monsanto’s PCB legacy, which shaped its public image. Its aggressive enforcement of seed patents, including lawsuits against farmers, generated negative publicity. And its lobbying against labeling laws made it a clear opponent for labeling advocates. Other companies developed GM crops and pesticides too, but Monsanto’s prominence made it a convenient symbol for broader concerns about industrial agriculture.

A Balanced View

The March Against Monsanto mobilized genuine public concern about food, agriculture, and corporate power, and it helped push issues such as labeling and pesticide accountability into public debate. It also spread claims that went beyond the evidence, particularly about the safety of eating approved GM foods. A balanced view recognizes both: concerns about pesticide use, resistance, consolidation, and transparency deserve attention and have support among scientists and economists, while claims that approved GM foods are inherently dangerous are not supported by major scientific reviews. Productive discussion requires distinguishing these issues rather than treating them as a single question.

Media Coverage and Public Perception

Media coverage of the first march varied widely. Some outlets reported organizer figures without qualification, while others noted they could not be verified. Coverage often framed the protests as a clash between activists and a powerful corporation, reinforcing Monsanto’s role as a symbol. Science journalists sometimes criticized protesters for ignoring evidence on GM food safety, while food and environmental reporters highlighted concerns about pesticides and corporate influence. The diversity of coverage reflected the diversity within the movement itself and the complexity of the issues it raised.

Readers revisiting this history can compare coverage from different outlets to see how framing shaped public understanding.

The Role of Celebrities and Influencers

Celebrities, wellness influencers, and documentary filmmakers amplified anti-GMO messages during the 2010s, increasing public attention. Some brought thoughtful critiques of industrial agriculture; others spread claims unsupported by evidence. Their reach often exceeded that of scientists and regulators, contributing to the gap in public and scientific opinion. Scientists responded with public outreach efforts, though research suggests that simply providing more information does not easily change strongly held views rooted in values and identity. Effective communication on contested food issues often involves listening to concerns and acknowledging legitimate issues alongside presenting evidence.

What Happened to the Organizers

As the movement grew, its organizing structure remained decentralized, with local volunteers coordinating events in their own cities. The founder and early organizers continued advocacy for a time, while many local groups evolved into organizations focused on labeling, pesticide policy, or local food systems. Social media pages associated with the movement continued posting content, sometimes drawing criticism for spreading unverified claims. The decentralized model enabled rapid growth but made it difficult to maintain consistent messaging and accuracy, a common challenge for internet-era movements.

Some former participants later shifted toward broader food system advocacy, including regenerative agriculture and local food initiatives.

Practical Takeaways

For readers interested in the issues the movement raised, practical steps include reading bioengineered disclosures and choosing organic or non-GMO verified products if desired, supporting policies for pesticide transparency and reduction, following independent research on agriculture and health, and engaging in local food systems. Evaluating claims critically and seeking out credible sources helps avoid both industry spin and activist misinformation. The goal is informed choice and evidence-based policy rather than allegiance to any side of a polarized debate.

Looking Ahead

Debates once centered on Monsanto now focus on gene editing, pesticide regulation, consolidation in agriculture, and food additives. Gene-edited crops may face lighter regulation in some countries, raising new questions about transparency. Glyphosate litigation has shifted after the 2026 Supreme Court ruling, and EPA’s updated assessment will shape future debates. Public trust in science and institutions remains a central challenge. The lessons of the March Against Monsanto, about mobilization, accuracy, and focusing on specific concerns, remain relevant for movements addressing these new issues.

Following these developments with attention to evidence will help readers engage constructively.

Remembering the March in Context

Looking back, the March Against Monsanto captured a moment when social media, food culture, and distrust of large corporations converged. It brought many people into food politics for the first time and pressured policymakers and companies to respond on labeling. It also contributed to polarization that has made constructive dialogue about agricultural technology difficult. Understanding both its achievements and its shortcomings helps current advocates, scientists, and policymakers work toward a food system that is safe, transparent, and fair.

The questions it raised about who controls food remain important today.

Where to Learn More Today

Readers interested in current debates can follow regulatory agencies such as the USDA and EPA, independent research institutions studying agriculture and food, consumer organizations focused on labeling and food safety, and farmer groups representing different perspectives. Comparing sources with different viewpoints, and checking whether claims cite peer-reviewed evidence, provides a fuller picture than relying on any single organization or social media feed.

Many of these organizations publish accessible summaries of research and policy developments.

The history of the March Against Monsanto also offers a reminder that public concern can shape markets and policy even when scientific debates continue, and that engaging respectfully with people who hold different views is essential for building food policies that command broad public trust and reflect both evidence and values across diverse communities.

Key Lessons in Brief

Social media can rapidly mobilize large numbers of people around food concerns. Specific, evidence-based demands are more persuasive than sweeping claims. Market shifts toward organic and non-GMO products show that consumer choices matter. Labeling compromises demonstrate how policy outcomes often differ from what advocates seek. And the persistent gap between scientific and public opinion highlights the need for trustworthy, transparent communication about food and agriculture.

These lessons apply well beyond genetic engineering, to any debate where science, values, and corporate power intersect in the food system.

They also show why trust, transparency, and accurate information matter as much as any single policy outcome in shaping how societies make decisions about new food technologies.

Frequently Asked Questions

What was the March Against Monsanto?

The March Against Monsanto was a global protest movement that began in 2013 from a single viral Facebook post and grew into coordinated demonstrations in hundreds of cities worldwide. Participants opposed genetically modified crops, pesticides, and corporate control of the food supply, calling for mandatory GMO labeling and stricter regulation of companies like Monsanto.

How did a Facebook post become a global movement?

In early 2013, one woman’s Facebook post proposing a march against Monsanto spread rapidly as others shared it and organized local events. Within months it became one of the largest coordinated protests about food, illustrating how social media can turn a single message into a worldwide movement around shared concerns and distrust.

Were the March Against Monsanto’s concerns valid?

Partly. The movement’s fears that eating approved GM foods is unsafe are not supported by scientific evidence. But its concerns about heavy herbicide use, corporate concentration of seeds and pesticides, and consumers’ right to know what is in their food reflect real issues that researchers and policymakers continue to debate.

Are GMO foods actually dangerous to eat?

No, according to major scientific organizations. The National Academies of Sciences, the World Health Organization, and others have concluded that approved GM foods are as safe to eat as their conventional counterparts. The strongest concerns about GMOs involve farming practices like herbicide use and corporate control rather than direct health effects of eating them.

What happened to the movement after Monsanto was acquired?

After Bayer bought Monsanto in 2018 and retired the Monsanto brand name, the large annual marches largely faded. The underlying concerns did not disappear, though; campaigns about glyphosate safety, corporate power in agriculture, food labeling, and pesticide regulation continued through other organizations, lawsuits, and advocacy efforts.

References

1. Scott SE, Inbar Y, Rozin P. Evidence for Absolute Moral Opposition to Genetically Modified Food in the United States. Perspectives on Psychological Science. 2016;11(3):315–324. PMID 27217243
2. Fernbach PM, Light N, Scott SE, et al. Extreme opponents of genetically modified foods know the least but think they know the most. Nature Human Behaviour. 2019;3(3):251–256. PMID 30953007
3. Pew Research Center. Public and Scientists’ Views on Science and Society. January 29, 2015. pewresearch.org
4. Christian Science Monitor (Associated Press). Global protests target Monsanto, genetically modified food. May 25, 2013. csmonitor.com
5. PBS SoCal. Worldwide March Against Monsanto Planned For Saturday. October 2013. pbssocal.org
6. Grist. As world marches against Monsanto, senators protect it from labeling laws. May 2013. grist.org
7. Nicolia A, Manzo A, Veronesi F, Rosellini D. An overview of the last 10 years of genetically engineered crop safety research. Critical Reviews in Biotechnology. 2014;34(1):77–88. PMID 24041244
8. Blancke S, Van Breusegem F, De Jaeger G, et al. Fatal attraction: the intuitive appeal of GMO opposition. Trends in Plant Science. 2015;20(7):414–418. PMID 25868652

Last updated: October 6, 2026