This is the fourth article in our endocrine disruption series — the one where everything we’ve talked about so far meets the one question that sits quietly in the background of all of this:
If science has been signalling endocrine disruption for years, why hasn’t our regulatory system kept up?
For years now, scientists studying endocrine disruption have been signalling something important: some chemicals don’t behave the way traditional toxicology expects them to. Instead, they nudge hormonal pathways at tiny concentrations, reshaping development, fertility, metabolism, or timing.
And when you look closely at how glyphosate and glyphosate-based herbicides were approved, a difficult truth comes into focus.
Our regulatory system simply wasn’t built to detect this kind of harm.
Not in New Zealand.
Not anywhere.
Once you see that, a lot of the confusion around glyphosate suddenly becomes much easier to understand.
This article does not revisit whether endocrine disruption matters — that groundwork has already been laid. Instead, it examines why regulatory systems built for a different kind of risk consistently fail to detect it.
Why Early Glyphosate Testing Missed Endocrine Disruption
When glyphosate was approved in the 1970s and 1980s, the field of endocrine disruption barely existed. Regulators weren’t looking for hormonal interference because the science wasn’t there yet. So glyphosate was tested for the things toxicologists knew how to measure at the time: poisoning, organ stress, tumour formation, and high-dose lethality.
What it wasn’t tested for are the very things endocrine science now considers fundamental — the quiet hormonal signals that shape development long before symptoms appear. That gap still exists today.
We are still living with that gap today.
Why Traditional Toxicology Misses Endocrine Disruption
Regulators still lean heavily on the old idea that “the dose makes the poison.” It’s tidy, predictable, and easy to test in a laboratory. Hormones don’t follow this rule. They operate at microscopic concentrations, where timing can matter more than quantity.
This means the traditional high-dose studies regulators rely on aren’t suited to detect endocrine effects. Those studies are designed to catch visible harm—organ damage, tumours, or changes you can see with a microscope. Endocrine disruption, on the other hand, is often invisible in the short term. The effects may show up months later, or even in the next generation.
So when regulators conclude that glyphosate shows “no endocrine effects,” the more accurate interpretation is simpler: the tests required weren’t capable of finding them.
Glyphosate Was Assessed — But Roundup Formulations Were Not
Another gap sits quietly in the background, often unnoticed until you go looking for it. New Zealand, like most countries, evaluates glyphosate as an active ingredient. But New Zealanders aren’t exposed to pure glyphosate. They’re exposed to Roundup and other formulations containing solvents, surfactants, preservatives, and stabilisers — some of which dramatically increase cellular uptake or carry toxicity of their own.
These mixtures were never subjected to the same long-term safety testing as glyphosate itself. In many cases, they were tested only for skin or eye irritation.
So when a regulatory document says “glyphosate is safe,” it is referring to a chemical that people almost never encounter by itself. The real-world products — the ones applied to school fields, paddocks, orchards, parks, waterways, and driveways — were never tested for endocrine disruption at all.
Why Current Safety Tests Can’t Detect Endocrine Disruption from Glyphosate
Our regulatory framework is very good at catching acute harm. It can spot poisoning, irritation, tissue damage, or tumours. What it struggles to catch are the slower, generational effects that arise from low-dose hormonal interference.
These are the kinds of disruptions that might show up as:
- shifts in puberty timing
- declining sperm counts
- changes in thyroid function
- metabolic changes affecting weight or insulin sensitivity
- altered reproductive patterns in wildlife and livestock
Individually, these impacts can be hard to trace. Together, they paint a picture that doesn’t fit neatly inside the tests regulators rely on. When the system isn’t built to look for endocrine disruption, it will confidently conclude that it doesn’t exist.
How Outdated Glyphosate Data Creates Regulatory Blind Spots
If you browse through MPI, EPA, and Ministry of Health reviews, a pattern becomes clear: New Zealand leans heavily on international regulators and industry-supplied studies. We have no routine endocrine testing, no requirement to screen glyphosate-based formulations for hormonal effects, and no long-term New Zealand data on generational endocrine outcomes.
In fact, there is no regulatory document in New Zealand that evaluates glyphosate formulations for modern endocrine endpoints. Not one.
This is not because the science is unsettled. It’s because the regulatory process was built in a different scientific era — and it hasn’t been meaningfully updated to reflect what we now know.
New Zealand’s Glyphosate Monitoring Gap — and Why It Matters
Endocrine disruption depends heavily on exposure timing, not just exposure amount. A tiny dose during pregnancy may have a very different effect than a larger dose later in life.
Yet New Zealand does not routinely test for glyphosate in food, water, soil, livestock, or people.
Without monitoring, we have no way of knowing who is exposed, when they are exposed, or how often. The absence of testing doesn’t indicate safety — it indicates uncertainty. It indicates uncertainty.
What Proper Endocrine Testing of Glyphosate Should Look Like
If New Zealand were to account for endocrine disruption properly, the process would look nothing like the one we rely on today. Modern testing would include receptor-level assays, low-dose studies, non-linear dose responses, pregnancy and fetal vulnerability, metabolic and thyroid endpoints, multi-generational studies, and full-formulation testing.
None of this is currently required.
Not because it isn’t important — but because our system hasn’t evolved to include it.
What New Zealand Must Do Next on Glyphosate and Endocrine Safety
Endocrine disruption is no longer a fringe idea. It’s one of the most widely recognised gaps in chemical safety frameworks worldwide. Yet we continue evaluating glyphosate-based herbicides with tools designed for a different kind of risk.
The scientific question — can glyphosate-based herbicides affect hormonal systems? — is not the hard part anymore. The harder question is the one New Zealand must now face:
How do we protect public health and the environment when the regulatory tools we rely on were never built to detect the kind of harm modern science is revealing?
What this series ultimately reveals is not a single regulatory failure, but a mismatch. Endocrine science now asks questions that chemical safety systems were never designed to answer. Until those tools evolve, the absence of detected harm will continue to be mistaken for reassurance — not just for glyphosate, but for any chemical assessed through the same outdated lens.
This article may close the endocrine disruption series, but the broader conversation is still unfolding. New research continues to emerge, and as it does, we’ll keep following it — question by question, gap by gap.
Part of The Endocrine Disruption Series: Understanding Hormones in a Chemical World
This article is part of The Endocrine Disruption Series, a four-part exploration of what the endocrine system is, how delicate it really is, and what happens when glyphosate-based weedkillers and other modern chemicals interfere with the body’s hormonal messaging system.
1. What Is the Endocrine System?
A clear introduction to hormones and how delicate the system really is.
2. Is Glyphosate an Endocrine Disruptor?
An investigation into the scientific evidence across species.
3. What Endocrine Disruption Means for People, Animals, and the Environment
Where endocrine disruption shows up in daily life and ecosystems.
4. Why Regulators Miss Glyphosate’s Endocrine Risks (You’re here)
Why New Zealand’s regulatory system still cannot detect the hormonal shifts modern science has uncovered.
Resources & References
Endocrine disruption is one of those topics where the deeper you look, the more the landscape shifts beneath your feet. The science is decades ahead of the regulations meant to protect us, and the studies below reflect that gap with uncomfortable clarity. Each one offers a clue — a signal that our current testing frameworks were never designed to detect the kinds of hormonal effects modern research now understands. If we want to make sense of where New Zealand’s regulatory blind spots truly are, this is where the picture starts to come into focus.
Understanding Endocrine Disruption
Endocrine Society – Scientific Statement on Endocrine-Disrupting Chemicals
A landmark review explaining how endocrine disruption works, why low-dose effects matter, and why traditional toxicology often fails to detect hormonal impacts.
https://www.endocrine.org/topics/edc/what-edcs-are
WHO/UNEP Report – State of the Science of Endocrine Disrupting Chemicals (2013)
A global scientific assessment showing why endocrine disruption requires different testing frameworks and why regulators often underestimate risk.
https://www.who.int/publications/i/item/9789241505031
Romano et al. (2010) – Prepubertal Exposure to Glyphosate Formulation Alters Testosterone and Testicular Development
An animal study showing reproductive and hormonal changes after exposure to a glyphosate-based herbicide.
https://pubmed.ncbi.nlm.nih.gov/20012598/
Howe et al. (2004) – Toxicity of Glyphosate-Based Herbicides to Frog Species
Shows endocrine-relevant developmental impacts in amphibians, including disruption in thyroid-related pathways.
https://pubmed.ncbi.nlm.nih.gov/15352482/
Vandenberg et al. (2012) – Hormones and Endocrine-Disrupting Chemicals: Low-Dose Effects and Non-Monotonic Responses
A pivotal paper explaining why low-dose endocrine effects are often missed in regulatory testing.
https://pubmed.ncbi.nlm.nih.gov/22419778/
European Food Safety Authority (EFSA) – Endocrine Disruption Guidance
Outlines how endocrine disruption should be assessed — compared with how most older pesticides were originally evaluated.
https://www.efsa.europa.eu/en/topics/topic/endocrine-active-substances
US National Academies Report – The Future of Toxicity Testing (2007)
A foundational document explaining why toxicology needs to move beyond high-dose “poison testing” to detect endocrine disruption.
https://www.nationalacademies.org/projects/BEST-U-03-08-A
Taken together, these studies show a pattern that’s impossible to ignore. Not dramatic, not explosive — but steady, consistent, and pointing in the same direction. Hormones shift. Development changes. Effects ripple across species and generations. And yet our approval processes still rely on tools built for another era. The science is evolving whether the regulations do or not. What we choose to do with that knowledge is the question that lingers long after the reading ends.
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