You’ve probably seen the headlines.
“TOXIC WEEDKILLER FOUND IN TAMPONS!”
“GLYPHOSATE 40X HIGHER THAN LEGAL LIMIT!”
“CAUSES CANCER, ALZHEIMER’S, ENVIRONMENTAL COLLAPSE!”
[My wife and I call tampons “minge plugs” – sorry, you’re just going to have to deal with that!]
I first saw someone going absolutely crazy at this on LinkedIn. It’s funny that she goes on to link the Daily Mail as one of her sources because her post reads just like something from the Daily Mail.
But hang on. Take a breath. Let’s look at what the numbers actually say and whether this is a real health risk or just another bout of chemophobia-fuelled panic.
TL;DR
Yes, there’s glyphosate in your tampon. No, it’s not giving you cancer.
Yes, it’s in your food. No, you’re not being poisoned.
Yes, it’s bad for bees and biodiversity. No, banning it alone won’t fix the problem.
What’s glyphosate?
Glyphosate is a herbicide. The main one. You’ve probably seen that weed killer, Roundup, in the garden centre – well, it’s in that. On a bigger scale, it’s sprayed all over crops like wheat, maize, soy and loads more (like the cotton that goes into making tampons). It stops plants from making certain amino acids, which they need to live, and so – surprise surprise – they die. Crops have often been modified to specifically be resistant to glyphosate, and so they’re left unharmed. It’s been around since the ‘70s and is the most-used pesticide in the world.
Cue decades of debate over whether it's the Devil’s actual unholy jizz or just an incredibly useful chemical that’s (mostly) fine if used properly.
The tampon thing
In May 2025, a report from Pesticide Action Network UK found glyphosate in tampons at levels up to 4 µg/L. This got reported as “40x the EU drinking water limit”, which is 0.1 µg/L per pesticide.
That’s true, but misleading.
The EU water limit isn’t a health-based threshold. It’s a legal policy level and it’s set extremely low on purpose. Like, zero tolerance low. Not ‘this will harm you’ low.
The actual EU Acceptable Daily Intake (ADI) for glyphosate is 0.5 mg/kg/day. For a 60 kg adult, that’s 30 mg/day safely put away in your body. The amount in a tampon? A few micrograms. You’d need to soak and consume thousands of them to get near the ADI. Please don’t do that.
And yes, mucous membranes (like the vagina) absorb chemicals more efficiently than skin. But there’s no evidence that this exposure route meaningfully increases your systemic glyphosate levels.
The 41% cancer Risk? Not what you think
Let’s me start by saying that yes, a 2015 review by the International Agency for Research on Cancer, part of the World Health Organisation, classified the weedkiller as “probably carcinogenic to humans”.1 This puts it in Group 2A, and the IARC’s classification focuses on whether an agent has the potential to cause cancer (hazard), not how likely it is to cause cancer at real-world exposure levels (risk).
Risk depends on dose, duration, and route of exposure, as well as individual susceptibility. What the IARC describe as “limited” human evidence, comes mostly from studies where exposure was very high – bigger, more frequent doses than for the general public. The animal evidence is from controlled studies at higher doses. So, keep that in mind.
Back to the headline figure: “41% increased risk of cancer”. This comes from a 2019 meta-analysis looking at people with high occupational exposure, mostly farmers and pesticide applicators.2 They found that those with the highest exposure had a 41% increased relative risk of non-Hodgkin lymphoma (NHL).
But here’s the key thing: the baseline risk of NHL is about 2%. A 41% increase makes it 2.8%. So the absolute risk increase is 0.8 percentage points.
Also, these people were using glyphosate in concentrated form, regularly, often without protection, for years. Whereas the general population is exposed to far, far lower levels – from food, water, and now apparently tampons.
A more recent meta-analysis looked at the association between occupational exposure to glyphosate and the risk of NHL and multiple myeloma (MM). They conclude there was “no overall evidence of an increased risk for both NHL and MM in subjects occupationally exposed to glyphosate.”3
I will note that a 2025 study fed rats doses of glyphosate at between 0.5 and 50mg/kg/day (remember, the ADI for glyphosate is 0.5 mg/kg/day) for 104 weeks, and the rats ended up with benign and malignant tumours.4 They conclude, “These results provide robust evidence supporting IARC’s conclusion that there is ‘sufficient evidence of carcinogenicity [of glyphosate] in experimental animals’.” Yes, this needs to be looked at more carefully, but it’s not a case for panic.
Regulatory agencies like EFSA, EPA, Health Canada, and Australia’s APVMA have all reviewed the data and concluded that glyphosate is unlikely to pose a cancer risk at real-world exposure levels.
So, unless you’re bathing in Roundup and chasing it with a tampon smoothie, your cancer risk is probably unaffected.
What about Alzheimer's, Parkinson’s, autism, etc?
I’m going to just be blunt here and say there’s no convincing evidence that glyphosate causes any of these: not Alzheimer's disease, not Parkinson’s disease and certainly not autism. There are studies in cells or animals that show oxidative stress or mitochondrial weirdness, but at doses hundreds to thousands of times higher than you’d ever get through normal exposure. And they often use glyphosate formulations (like Roundup), not the chemical itself.
But human data is, overall, pretty flimsy. No good extensive epidemiology using levels the public comes into contact with, no clear mechanisms and lots of cherry-picking. The only one with nuance here is Parkinson’s, and that all comes from a Lancet paper that talks about case studies5 and one epidemiological study (looking at farmers with already high exposures) that suggests there might, maybe, be a possible association between glyphosate exposure and Parkinson’s.6
The data are still preliminary in this Parkinson’s case but definitely warrant looking a little deeper, especially for people who happen to work in agriculture and spend far too long wading around in Roundup.
So again, if there’s a risk here, it’s theoretical at best.
Bees, biodiversity and the bigger mess
Here’s where we might have a problem. Glyphosate isn’t great for ecosystems. It messes with soil microbes, aquatic critters, and yes, our beloved bees. While glyphosate doesn’t kill bees directly, it does disrupt their gut bacteria, which weakens their immunity.7 It can also mess with their navigation and foraging behaviour at field-relevant concentrations when exposed over a long time.8 Plus, by nuking wildflowers and creating monocultures, it removes the stuff they need to survive.
So no, glyphosate isn’t a bee-murdering demon. But it’s part of a system that’s slowly strangling biodiversity, and its role in that deserves scrutiny.
Still legal, still controversial
Glyphosate is still approved in most places:
EU reapproved it in 2023 for 10 years.
UK, US, Canada and Australia all allow it.
Luxembourg banned it.
Germany, Austria, Mexico, and others have partial or phased restrictions.
There’ve been huge lawsuits in the US, awarding billions in damages to people with cancer allegedly linked to glyphosate. That’s driven a lot of public fear, but the legal standard of evidence is not the same as the scientific one.
So, Should You Panic?
In a word: no.
Glyphosate is not safe in all contexts, but the levels we’re exposed to are low.
The tampon story is mostly a red herring – mildly gross, but not dangerous.
The cancer risk is real for heavy, occupational exposure, but vanishingly small for most people.
Environmental concerns are legit, but they’re about ecosystem fragility, not acute toxicity.
The real issue isn’t glyphosate. It’s how we farm.
If you’re angry, be angry at the industrial agriculture model that made this seem normal, not at the molecule.
Why am I writing this?
Science is really bloody hard. The data are often complex, and if you’re not familiar with scientific papers and looking at experimental setups, data analysis and interpretations, it's really easy to jump to the wrong conclusion. This story ran in the Guardian, and to be honest, they did a really shitty job of being objective. There’s no reason for most people in the public to have the skills to look through the data and draw a sensible conclusion. If COVID taught us anything, it’s that people going ‘do their own research’ is rarely helpful. Without a good scientific eye, it’s far too easy to leap to the wrong conclusion and whip people up into panic and fear. Science journalists need to do a better job and talking about data, explaining nuances and helping people understand hazards and risks.
References
1. IARC Monograph on Glyphosate. https://www.iarc.who.int/featured-news/media-centre-iarc-news-glyphosate.
2. Zhang, L., Rana, I., Shaffer, R. M., Taioli, E. & Sheppard, L. Exposure to glyphosate-based herbicides and risk for non-Hodgkin lymphoma: A meta-analysis and supporting evidence. Mutat Res Rev Mutat Res 781, 186–206 (2019).
3. Donato, F., Pira, E., Ciocan, C. & Boffetta, P. Exposure to glyphosate and risk of non-Hodgkin lymphoma and multiple myeloma: an updated meta-analysis. Med Lav 111, 63–73 (2020).
4. Panzacchi, S. et al. Carcinogenic effects of long-term exposure from prenatal life to glyphosate and glyphosate-based herbicides in Sprague–Dawley rats. Environmental Health 24, 36 (2025).
5. Eriguchi, M. et al. Parkinsonism Relating to Intoxication with Glyphosate. Intern Med 58, 1935–1938 (2019).
6. Bloem, B. R. & Boonstra, T. A. The inadequacy of current pesticide regulations for protecting brain health: the case of glyphosate and Parkinson’s disease. The Lancet Planetary Health 7, e948–e949 (2023).
7. Motta, E. V. S., Raymann, K. & Moran, N. A. Glyphosate perturbs the gut microbiota of honey bees. Proceedings of the National Academy of Sciences 115, 10305–10310 (2018).
8. Almasri, H., Liberti, J., Brunet, J.-L., Engel, P. & Belzunces, L. P. Mild chronic exposure to pesticides alters physiological markers of honey bee health without perturbing the core gut microbiota. Sci Rep 12, 4281 (2022).
“The real issue isn’t glyphosate. It’s how we farm.”
That was probably the single best round-up (heh, sorry, couldn’t resist) of “The Round-Up Problem” I’ve seen, because it’s one of the few to squarely identify that as the core problem. No the evil chemicals themselves, as such (thank you also for “chemophobia”), but the whole monoculture-focussed, “nature is there to be plundered” attitude of modern farming.
Of course, with a population of 7 billion to feed, arable farmland vanishing under the press of housing, and water access increasingly fraught, (not to mention climate change, of course - there, I said it!), food production is pretty bloody fraught to start with. There are no simple answers - not going vegan or vegetarian (a lot of useful, edible animals thrive in marginal lands that can’t produce human-edible food plants at any scale)(but eating LESS meat would definitely help), not going organic (it’s still a focus on monocultural food production, just with different inputs), not a wholesale turn to regenerative or multi-crop agricultural practices (although it doesn’t harm), not even trying to focus on native food production to stop forcing farmland to grow what doesn’t naturally thrive there (although again, that won’t harm).
So we need these discussions to say “if we can’t use herbicides, how do we feed everyone?”.
(I have heard it said that there is, in fact, enough food for everyone, but it’s incredibly unevenly distributed because of the savage wealth imbalances on the planet, plus food wastage. I’d be interested to follow that one up).