Think glyphosate is safe? That depends—are we talking about the pure chemical tested in labs, or the full product actually being sprayed on farms, footpaths, and school grounds?
What’s being sprayed in the real world isn’t pure glyphosate—it’s a chemical cocktail. One of the most widely used of these formulations is Roundup.
Glyphosate-based weed killers contain surfactants, solvents, and other additives—ingredients designed to make the herbicide work better by helping it stick to leaves and penetrate plant cells.
But here’s the problem: some of those so-called “inert” ingredients—especially POEA (polyethoxylated tallow amine), a surfactant used to help glyphosate penetrate plant cells—may be even more toxic than glyphosate itself. Yet they’re rarely tested, barely regulated, and often kept secret.
So why are regulators testing only one part of the mixture… when the public is exposed to all of it?
What’s Really in a Bottle of Roundup?
As mentioned earlier, glyphosate-based weed killers such as Roundup are more than glyphosate. They contain a mix of ingredients, many of which are labeled as “inert.” That word sounds harmless, right? But it’s misleading. These so-called “inert” additives aren’t biologically inactive. In fact, some may be even more toxic to human cells than glyphosate itself.
A 2014 study published in Environmental Sciences Europe found that glyphosate-based herbicides—including Roundup—were significantly more toxic to human cells than glyphosate alone. In some cases, the formulations were up to 1,000 times more toxic. The researchers pinpointed ethoxylated surfactants—used to help glyphosate penetrate plant cells—as the main culprit.
This clearly confirms that the adjuvants in Roundup formulations are not inert.
— Mesnage et al., 2014
So, Why Aren’t We Testing the Full Product?
This is where things get concerning.
Regulatory agencies—including the Environmental Protection Agency (EPA) in the U.S. and the Ministry for Primary Industries (MPI) here in New Zealand—only test the “active” ingredient when evaluating herbicide safety. That means glyphosate gets scrutinized, but the rest of the mixture gets a free pass.
It’s like testing vodka for safety while ignoring the Red Bull in a vodka-Red Bull mix—you’re missing the actual combination people consume.
A Regulatory Blind Spot With Real-World Impacts
Here’s the problem: Glyphosate alone may be considered “low toxicity” in isolation (depending on the study), but in combination with ingredients like POEA (polyethoxylated tallow amine), a surfactant used to help glyphosate penetrate plant leaves, the risk profile changes dramatically. These surfactants can:
- Increase glyphosate absorption through the skin
- Disrupt human cell membranes and mitochondrial function
- Amplify hormone-disrupting effects
And many of these co-formulants are not disclosed to the public. Some are protected as “confidential business information,” meaning that even councils, schools, farmers, and medical professionals may have no idea what they’re dealing with.
Want to go deeper?
We’ve unpacked what New Zealand’s own government report quietly revealed about these unknown ingredients in glyphosate-based herbicides—and why even regulators admit they don’t have the full picture.
Read it here: The ‘Inert’ Ingredient Illusion
And Yes, It’s Legal
So glyphosate-based weed killers such as Roundup get the green light—not because they’re proven safe as a whole, but because only part of them is ever tested. The rest? Hidden in plain sight.
Curious how regulators decide what’s “safe”? This article breaks it down.
New Zealand’s regulatory framework, like many others around the world, approves herbicides based on their active ingredients, not the complete formulation. This allows products like Roundup to be legally sold and widely used—even though the full mixture may pose significantly higher risks.
A Public Health Concern Hiding in Plain Sight
This matters.
If you’re worried about glyphosate, you’re not wrong—but you may be focusing on the wrong piece of the puzzle. The real threat may lie not in glyphosate alone, but in the mix it comes with.
Glyphosate-based weed killers such as Roundup are what we’re actually exposed to—in our food, our parks, our waterways, and even our own backyards. Imagine your child playing on recently sprayed grass. What’s entering their skin may be far more than just glyphosate.
Final Thought
Regulators continue to repeat the same refrain: glyphosate is safe when used as directed. But what if it’s not the glyphosate we need to be worried about?
If the additives in Roundup are even more toxic than the herbicide itself—and if they’re not being properly studied or disclosed—then how can we truly call it safe?
It’s time to stop looking at glyphosate in a vacuum. Because the real danger may not be what’s on the label—but what’s been deliberately left off.
Resources & References
We don’t expect you to take our word for it—and you shouldn’t. Below is a selection of peer-reviewed studies, regulatory documents, and related articles that shed light on what’s really inside glyphosate-based herbicides like Roundup. This isn’t just about glyphosate. It’s about the chemical cocktail we’re all being exposed to—and how little of it has truly been examined.
Ethoxylated adjuvants of glyphosate-based herbicides are active principles of human cell toxicity
Mesnage, R. et al. (2014).
This peer-reviewed study revealed that Roundup formulations are significantly more toxic to human cells than glyphosate alone. Surfactants like POEA were identified as key toxic components.
https://enveurope.springeropen.com/articles/10.1186/s12302-014-0014-5
Trends in glyphosate herbicide use in the United States and globally
Benbrook, C. (2016).
This study outlines the explosive global increase in glyphosate use over time, raising concerns about cumulative exposure and regulatory oversight.
https://enveurope.springeropen.com/articles/10.1186/s12302-016-0070-0
Glyphosate: Interim Registration Review Decision (2020)
U.S. Environmental Protection Agency (EPA).
The EPA’s official position on glyphosate safety—but based only on the active ingredient, not full commercial formulations.
https://www.epa.gov/ingredients-used-pesticide-products/glyphosate
EFSA (European Food Safety Authority).
Conclusion on the peer review of the pesticide risk assessment of glyphosate (2015)
This assessment confirms that EU regulators evaluated glyphosate alone, acknowledging gaps in data on co-formulants.
https://www.efsa.europa.eu/en/efsajournal/pub/4302
Related Articles NoMoreGlyphosate.nz
Why Glyphosate Isn’t Just a Weed Killer — It’s a Public Health Issue
Explores how glyphosate affects more than weeds—touching human health, soil systems, and public trust.
Why Glyphosate Isn’t Just a Weed Killer
What “Safe Levels” Really Mean — And Why They Keep Creeping Up
Unpacks the regulatory logic behind residue limits—and why they’re often based on incomplete science or industry pressure.
What “Safe Levels” Really Mean
Further Reading: Books That Go Deeper
If this article raised questions for you, you’re not alone. The following books offer eye-opening investigations into glyphosate, regulatory failures, and the hidden dangers of chemical formulations:
Whitewash: The Story of a Weed Killer, Cancer, and the Corruption of Science
By Carey Gillam
A hard-hitting exposé revealing how Monsanto manipulated science, silenced critics, and sold the illusion of safety—while key risks were ignored.
Whitewash [our review]
Toxic Legacy: How the Weedkiller Glyphosate Is Destroying Our Health and the Environment
By Stephanie Seneff
A controversial but compelling look at how glyphosate may be contributing to chronic illness, microbiome disruption, and environmental breakdown.
Toxic Legacy [our review]
The Monsanto Papers: Deadly Secrets, Corporate Corruption, and One Man’s Search for Justice
By Carey Gillam
The inside story of the landmark Roundup cancer trial, exposing internal documents that revealed just how much Monsanto knew—and kept hidden.
The Monsanto Papers [our review]
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