If there is one thing that has radically changed my perspective in recent years, it is discovering what lies behind the products we use every day. And one of those that shocked me the most was toothpaste. Yes, the one we use at least twice a day, the one we let come into contact with the oral mucosa (one of the most permeable parts of the body), and the one we sometimes even end up swallowing unintentionally.
As I always tell you: not everything that is sold is safe, let alone healthy. The most common thing is that your toothpaste… is poisoning you, literally. And no, that is not just a figure of speech or an exaggeration to get attention. It is a fact.
When I started to thoroughly investigate the formulas of the best-selling brands, I realized that almost all of them have one thing in common: they are full of ingredients that no one should put in their mouth. Ingredients that come from petroleum, that disrupt your hormones, that are under review in Europe for their potential carcinogenic or neurotoxic effects, or even for their ability to affect fetal development. Ingredients that have been banned in other products but are still there… in something as basic as toothpaste.
What surprised me most was discovering that many of these substances are used simply because they are cheap. Not because they are safe, necessary, or effective… but because they make the final product cheaper. But at the expense of your health.
We are talking about toothpastes that you can buy for less than two euros, and which seem like a bargain. But no one tells you that inside that tube are compounds that can accumulate in your body with daily use, and that in the long term contribute to the toxic cocktail we are enduring without realizing it. The skin and mucous membranes are not impenetrable barriers. Everything that gets in there, gets into you. And we are not talking about a one-time exposure. We are talking about something you use every day, since you were a child.
And yes, I know what some people think: “if it’s for sale, it must be safe”. But I’m sorry to tell you that this is not entirely true. European regulations on cosmetics and personal care are full of loopholes. Ingredients are evaluated individually, without taking into account combined exposure. Many studies are old, with clear biases, and in many cases funded by the very industries that manufacture the ingredients. Furthermore, the established safety limits do not always consider cumulative or hormonal effects, or the impact on pregnant women and children.
In fact, there are substances that have been used for decades without issue, until their toxicity is suddenly discovered and they are banned. A clear case is triclosan, which was removed from soaps due to its hormonal effects, but which remained (and in some cases still remains!) present in toothpastes. How is that possible? Well, because many public health decisions lag far behind science, and even further behind ethics.
And if you are here reading this, it is because you too want to know more. Because you are tired of using products without knowing what is in them. And because, like me, you are starting to question everything.
This article is not just a critique. It is a guide to truly understanding what is in your toothpaste and why it matters. Because hormonal health is not a luxury, it is a necessity. And it starts with something as small as the act of brushing your teeth.
Triclosan: the endocrine disruptor that still appears in toothpaste
Triclosan was originally incorporated into products such as toothpaste, soaps, deodorants, and even sponges or textiles because it inhibited bacterial growth. For years, it was promoted as a “plus” for oral hygiene, with the promise of reducing plaque and gingivitis. In fact, in 2013, a Cochrane review went so far as to say that its use could reduce plaque by up to 22% and gum bleeding by 48% compared to toothpastes that only contained fluoride. On the surface, it sounds good.
But when you dig a little deeper… the landscape changes.
What effects does it have on our health?
Various studies have shown that triclosan directly affects the endocrine system. In other words, it acts as a hormonal disruptor: it mimics or blocks the natural functioning of our hormones, causing alterations in the thyroid, the reproductive system, and fetal development.
One of the findings that shocked me the most was that, according to the NHANES study in the U.S., triclosan was detected in more than 74% of the urine samples analyzed. And we are not talking about occasional exposure, but constant accumulation. In other studies, such as those carried out in Canada and China, the presence was also extremely high: between 70% and 99.5% of people had it in their bodies.
And it is not just a simple presence. Relationships have been observed between high levels of triclosan and:
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Reduced sperm count in men.
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Thyroid dysfunction.
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Increased risk of allergies and dermatitis in children exposed during pregnancy.
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Liver fibrosis and tumors in animal studies, after prolonged exposure.
Perhaps the most alarming finding was a recent study with more than 300 pregnant mothers and their babies: doubling the levels of triclosan in the mother’s urine also doubled the risk of the baby developing allergic rhinitis. All this, from an ingredient legal in a toothpaste. It is terrifying.
And what does European regulation say?
Until recently, this ingredient was present in almost all antibacterial toothpastes on the market. In 2024, the EU updated its regulation: up to 0.3% concentration is permitted in adult toothpastes, but it is banned in infant formulas (under 3 years) and in mouthwashes. Furthermore, it requires specific labels that warn of the content.
But, and this is important, products that were already on the market before the rule can continue to be sold until the end of 2025. In other words: you could be using a toothpaste with triclosan today, thinking it is approved… when in reality it is already considered risky. This reflects one of the great failures of the system: regulation lags far behind science, and does not contemplate cumulative exposure or combined effects with other toxic chemicals.
Propylene glycol: what is a petroleum derivative doing in your mouth?
Propylene glycol (PEG) is a synthetic alcohol derived from petroleum, present in more than 70% of conventional toothpastes. Its function? To act as a humectant, solvent, and stabilizer. The problem? Its ease of penetrating the skin and mucous membranes, and its potential to transport other toxins into the body.
- A study by Toxicology and Applied Pharmacology (2006) showed that repeated exposure to propylene glycol can increase skin permeability, facilitating the absorption of toxic substances.
- The FDA classifies it as “generally safe,” but in prolonged and cumulative exposures, it can cause irritation, sensitization, and mild systemic effects, especially in children and people with sensitive skin.
- Furthermore, it can contain ethylene oxides and 1,4-dioxane as residual contaminants, both classified as possible human carcinogens by the IARC.
And why is it allowed? Because legislation evaluates ingredients in isolation and in theoretical minimum doses, without considering the cumulative effect or toxic synergies.
As I always say: just because something is in your bathroom doesn’t mean it should be in your body.
PEGs: the invisible thickeners no one tells you about
An ingredient that appears very frequently: PEGs, or polyethylene glycols. Specifically, they are present in more than 50% of conventional formulas. Their name might seem harmless or simply technical, but behind it lies a reality that many brands would prefer you didn’t know.
PEGs are petroleum derivatives used as thickeners, emulsifiers, and stabilizers. Their function is purely functional: they help the texture of the toothpaste be homogeneous, pleasant, and remain stable over time. The problem is not just the ingredient itself, but what they bring with them.
During their manufacture, PEGs can be contaminated with ethylene oxide and 1,4-dioxane, two compounds considered potentially carcinogenic to humans by the IARC (International Agency for Research on Cancer). Although European regulations allow their use provided they are below certain thresholds, the truth is that no one is analyzing how these residues act when we use them daily, several times a day, for years.
What surprised me most is that PEGs continue to be considered “inert ingredients,” when there are already in vitro studies showing how they can increase the permeability of the skin and mucous membranes, facilitating the entry of other toxic substances into the body. In other words: they might not only be a problem in themselves, but they can also become a gateway for other toxins.
And why are they still allowed? The answer is always the same: they are evaluated in isolation, in theoretical doses, without contemplating the real cumulative effect or the synergies with other ingredients in the same product. In fact, the European Scientific Committee on Consumer Safety’s own report acknowledges that no specific repeated oral exposure tests are required for these compounds.
This is not about fear-mongering. It is about questioning what we use every day without thinking. Because if more than half of the toothpastes sold in the supermarket contain PEGs contaminated with known toxins, shouldn’t we demand cleaner, more transparent, and safer formulas?
Sodium fluoride - FLUORIDE: friend of your teeth or ally of your hormones?
When reviewing ingredients in commercial toothpastes, there is one that always appears: sodium fluoride (NaF). It is practically in almost 95–100% of conventional formulas, and many people consider it essential to prevent cavities. However, there are very important aspects that we should know before assuming it is harmless.
Although it is true that in safe doses fluoride helps remineralize tooth enamel, its systemic effect is not neutral.
In the scientific literature, there are serious studies that link it to alterations in thyroid function. This happens especially when it accumulates in the body from multiple sources (fluoridated water, toothpaste, processed foods). The evidence indicates that high concentrations can raise TSH levels and reduce T3 and T4, interfering with the hormonal balance.
But even more worrying: there is research linking chronic fluoride exposure to decreases in IQ in children, especially when exposure occurs in early stages of development. A systematic review published in JAMA Pediatrics determined that elevated levels in drinking water were associated with a drop in average IQ of 5 to 7 points.
And the regulations allow it, yes, but with a major shortcoming: there is no control over the actual amount we absorb daily. European regulation establishes a maximum concentration in toothpastes (usually between 1,000 and 1,500 ppm), but it does not take into account the simultaneous exposure from multiple sources. Nor does it require long-term cumulative toxicity studies, or contemplate vulnerability during stages like pregnancy or childhood.
For the neurological development of the fetus or infant, these exposures can be irreversible. That is why, as I always tell you, not everything that is permitted is automatically healthy. Especially in a daily-use product that we accidentally ingest and use every day since childhood.
DEA (Diethanolamine): the foaming agent with a hidden risk
DEA (diethanolamine) is a synthetic organic compound derived from ethylene oxide and ammonia, frequently used in toothpastes and cosmetic products as a foaming agent, emulsifier, and thickener. It provides a creamy texture and a visual sense of cleanliness due to the foam, but from a toxicological standpoint, it is far from harmless.
One of the main problems with DEA is its ability to react with nitrosating agents present in the products or in the body itself, forming nitrosamines, a group of compounds classified by the IARC (International Agency for Research on Cancer) as probable human carcinogens (Group 2B). These nitrosamines have shown, in multiple studies on rodents, an association with liver, kidney, and digestive tract tumors.
Furthermore, research published in journals such as Toxicology Letters and Environmental Health Perspectives has shown that prolonged exposure to DEA can cause hormonal disruptions, especially regarding thyroid and reproductive function, as well as liver and kidney damage.
Regarding its presence, it is estimated that at least 30–40% of conventional toothpastes contain DEA or derivatives such as Cocamide DEA or Lauramide DEA, often without clear warnings on the label. The European Union allows its restricted use, but does not ban the formation of nitrosamines, provided certain impurity levels are not exceeded, which leaves a window open to chronic exposure through daily use. Furthermore, studies on dermal and mucosal absorption show that, although the compound has low transcutaneous penetration, its accumulation in the body is possible due to repeated use and in combination with other substances.
The presence of DEA in oral products is especially alarming because of the direct and prolonged contact with the oral mucous membranes, which are highly permeable and represent a direct path to the circulatory system. And most worrying: it is an unnecessary ingredient from a functional point of view, as there are natural, non-toxic alternatives with the same efficacy. In summary, the use of DEA represents an avoidable chemical risk, which remains on the market due to its low industrial cost and its ability to improve the sensory experience of the product, but which does not justify the potential damage to health.
How did we get here?
At what point did we accept that something we use every day—like toothpaste—contains petroleum derivatives, substances that disrupt our hormonal system, or ingredients that were banned in the past and are now sneaking back in through the back door? Why do we still believe that “if it’s on the market, it must be safe”? The reality is different: cosmetic safety is measured in a laboratory, but the human body is not an isolated laboratory. It is a complex, sensitive ecosystem, and what we accumulate day by day—however small it may be—can have consequences we don't fully understand yet.
I am not writing this to create fear, but to invite you to question. To look at labels with new eyes. To understand that what is “normal” is not always what is right. Because what is truly radical today is choosing what is healthy.
What if all of this wasn’t an exaggeration, but information they simply don't want you to have so readily available? And what if taking care of your health starts exactly with what you didn’t think was a risk?
—Verónica, founder of Banbu
