We’re told that breast is best. It’s the gold standard—rich in antibodies, tailored nutrition, and the emotional bond it fosters between mother and child.
But what happens when that purest of first foods may not be so pure after all?
Concerns are growing that glyphosate, the active ingredient in Roundup and similar weedkillers, might be showing up in breast milk. Even the possibility is enough to warrant serious scrutiny. After all, this is about infants—tiny humans with underdeveloped organs, permeable gut linings, and immune systems still finding their feet.
So, is glyphosate really in breast milk? Let’s unpack what we know—and what the industry would prefer we didn’t ask.
The 2014 Bombshell That Sparked Alarm
In 2014, a pilot study funded by Moms Across America and conducted by a lab affiliated with the University of California found glyphosate residues in the breast milk of 3 out of 10 American mothers tested. The levels exceeded what’s legally allowed in U.S. drinking water.
The results spread quickly across concerned parent networks, environmental circles, and grassroots media. The message? Glyphosate may be bioaccumulating in human tissue, contrary to industry claims that it is quickly excreted via urine.
While the sample size was small and not peer-reviewed, the emotional weight of the findings hit home for many: If this weedkiller is in breast milk, then babies are being exposed during their most critical window of development.
The Pushback and Scientific Debate
Regulators and industry moved fast to discredit the study. The U.S. EPA publicly stated that glyphosate is “not expected” to accumulate in body fat or breast tissue. Monsanto called the study flawed and misleading.
But here’s the catch: no large-scale, peer-reviewed follow-up study was ever conducted to truly settle the question. Not by Monsanto. Not by the EPA. Not by independent health agencies. If they’re so confident in its safety, why not test 1,000 mothers and publish the results?
Could it be that the risk of confirming exposure is simply too inconvenient?
Meanwhile, glyphosate has been detected in urine samples from people all over the world, including children. If it’s in the body, and we know breast milk is a pathway for excretion of many contaminants, is it really that implausible that glyphosate could be making its way to the most vulnerable among us?
What Later Research Tells Us
Studies conducted in Germany and elsewhere since 2014 have found glyphosate residues in urine but often not in breast milk. This has been used as a rebuttal—but the picture isn’t quite so clear.
A 2019 pharmacokinetic review led by Dr. Robin Mesnage highlighted that while glyphosate may not bioaccumulate in the classical sense (like heavy metals), chronic low-level exposure may still result in glyphosate being present in breast milk, particularly if exposure is frequent or dietary.
Animal studies have shown glyphosate can cross the placenta and accumulate in fetal tissue. So even before breastfeeding begins, the exposure may already have happened.
And then there’s this: no one has rigorously studied whether glyphosate’s metabolites, like AMPA, or co-formulants in Roundup, accumulate differently in breast tissue. The focus is almost always on “pure glyphosate”—not the formulations sprayed on playgrounds, school fields, and food crops.
Why This Still Matters
Even if the scientific jury is still out, we have enough circumstantial and biological evidence to be concerned. Breast milk is not just any exposure route. It’s the lifeline for newborns. And the potential health effects of even trace amounts of glyphosate are not trivial.
Glyphosate has been linked to:
- Disruption of the gut microbiome (critical for immune development)
- Interference with hormone systems (especially estrogen and thyroid)
- Oxidative stress and DNA damage
These are not the kinds of things you want to introduce to a developing infant.
The Need for Transparency and Testing
If governments and regulators are serious about protecting child health, this is where they prove it. Not with words, but with data.
We need properly funded, independent testing of breast milk in New Zealand. Not just 10 samples. Hundreds. Across regions, dietary habits, and exposure profiles. And we need to ask: is there a correlation between maternal diet and residue levels?
Until then, we’re flying blind—and letting industry narratives substitute for evidence.
Wouldn’t it be something if New Zealand were the first country to take this issue seriously?
Final Thought: A Critical Wake-Up Call
Most parents go to great lengths to give their babies the healthiest start in life. They buy organic baby food. Filter their water. Research every product.
But what about the unseen exposures—like what’s drifting in through the kitchen window or baked into the toast?
If even one child is ingesting glyphosate in breast milk, that should be enough to trigger a national conversation. Because when the first food is no longer safe, we’re not just failing science. We’re failing our future.
Resources & References
The issue of glyphosate in breast milk isn’t fully settled—but it’s far from baseless. And while scientists may still be debating the details, these findings suggest we shouldn’t ignore the possibility.
Moms Across America & Sustainable Pulse (2014)
Pilot breast milk testing study suggesting glyphosate presence. While not peer-reviewed, it sparked global concern.
https://www.momsacrossamerica.com/glyphosate_testing_results
Glyphosate exposure in pregnancy and shortened gestational length: a prospective Indiana birth cohort study
A study conducted by Indiana University found that over 90% of pregnant women had detectable levels of glyphosate in their urine. The study also observed a significant correlation between higher glyphosate levels and shortened gestational lengths.
Link to study
Determination of Glyphosate Levels in Breast Milk Samples from Lactating Women in a Rural Area from Paraná State, Brazil
This study analyzed breast milk samples from lactating women in a rural area of Brazil and detected glyphosate residues in all samples tested.
Link to study
These studies provide a foundation for discussing the presence of glyphosate in human biological samples and its potential implications for infant health. They highlight the need for further research and more extensive testing to fully understand the risks associated with glyphosate exposure through breastfeeding.
Related Articles on NoMoreGlyphosate.nz
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Read about the hidden fertility risk here
Glyphosate and Preterm Birth: What the Research Shows
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Read about Glyphosate Exposure and Preterm Birth here
How Glyphosate Could Be Affecting Women’s Fertility
From hormone disruption to ovarian effects, this article unpacks the multiple ways glyphosate could be interfering with female reproductive health.
Read how Glyphosate Threatens Women’s Fertility here
Why Glyphosate Isn’t Just a Weed Killer — It’s a Public Health Issue
Beyond the backyard spray bottle lies a bigger story: how glyphosate is turning up in our food, water, and bodies—and why that should concern everyone.
Read why Glyphosate is a Public Health Issue
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