If there's one thing that has radically changed my perspective in recent years, it's discovering what lies behind the products we use every day. And one of the most impactful 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 accidentally swallow.
As I always tell you: not everything that is sold is safe, let alone healthy. Most likely, your toothpaste... is literally poisoning you. And no, it's not just a figure of speech or an exaggeration to get attention. It's a fact.
When I started to thoroughly research the formulas of 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 alter your hormones, that are under review in Europe for their possible carcinogenic, neurotoxic effects, or even their ability to affect fetal development. Ingredients that have been banned in other products, but that 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, or necessary, or effective... but because they allow the final product to be cheaper. But at the cost of your health.
We are talking about toothpastes that you can buy for less than two euros, and that seem like a bargain. But no one tells you that inside that tube there 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 enters there, enters you. And we are not talking about a one-time exposure. We are talking about something you use every day, since you were little.
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 cosmetic and personal care regulation is full of loopholes. Ingredients are evaluated individually, without considering 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, hormonal effects or the impact on pregnant women and children.
In fact, there are substances that have been used for decades without problems, 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 does!) present in toothpastes. How is this possible? Well, because many public health decisions lag far behind science, and even further behind ethics.
And if you're reading this, it's because you also want to know more. Because you're tired of using products when you don't know what's in them. And because, like me, you're starting to question everything.
This article is not just a critique. It's a guide to truly understand what's in your toothpaste and why it matters. Because hormonal health is not a luxury, it's 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 toothpastes, 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 stated that its use could reduce plaque by up to 22% and gum bleeding by 48% compared to toothpastes containing only fluoride. On the face of it, it sounds good.
But when you dig a little deeper... the picture changes.
What effects does it have on our health?
Several studies have shown that triclosan directly affects the endocrine system. That is, it acts as an endocrine disruptor: it mimics or blocks the natural functioning of our hormones, generating alterations in the thyroid, the reproductive system, and fetal development.
One of the facts that struck me the most was that, according to the NHANES study in the US, triclosan was detected in more than 74% of the urine samples analyzed. And we are not talking about occasional exposures, but constant accumulation. In other studies, such as those carried out in Canada and China, the presence was also very high: between 70% and 99.5% of people had it in their bodies.
And it's not just a mere 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 dysfunctions.
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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 data came from 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 a legal ingredient in toothpaste. It's 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 the regulation: up to 0.3% concentration is allowed in adult toothpastes, but it is prohibited in infant formulas (under 3 years old) and mouthwashes. In addition, it requires specific labels that warn of the content.
But, and this is important, products that were already on the market before the standard can continue to be sold until the end of 2025. That is to say: you may be using a toothpaste with triclosan today, thinking that it is approved... when in reality it is already considered risky. This reflects one of the major failures of the system: regulation lags far behind science, and does not consider either 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 accumulated exposures, it can cause irritation, sensitization, and mild systemic effects, especially in children and people with sensitive skin.
- In addition, it may contain ethylene oxides and 1,4-dioxane as residual contaminants, both classified as possible human carcinogens by IARC.
And why is it allowed? Because legislation evaluates ingredients in isolation and at 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 nobody tells you about
A very frequently recurring ingredient: PEGs, or polyethylene glycols. Specifically, they are present in over 50% of conventional formulas. Their name may seem harmless or merely technical, but behind it lies a reality that many brands prefer you not to know.
PEGs are petroleum derivatives used as thickeners, emulsifiers, and stabilizers. Their function is purely functional: they help the toothpaste's texture 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 as long as 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 are still 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. That is to say: not only could they 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, at theoretical doses, without considering the actual cumulative effect or synergies with other ingredients in the same product. In fact, the European Scientific Committee on Consumer Safety's own report acknowledges that no specific tests for repeated oral exposure are required for these compounds.
This is not about alarming for the sake of alarming. It is about questioning what we use every day without thinking. Because if more than half of the toothpastes sold in supermarkets contain PEGs contaminated with recognized toxins, shouldn't we demand cleaner, more transparent, and safer formulas?
Sodium Fluoride - FLUORIDE: friend to your teeth or ally to your hormones?
When reviewing ingredients in commercial toothpastes, one always appears: sodium fluoride (NaF). It is practically present in almost 95–100% of conventional formulas, and many people consider it indispensable for preventing cavities. However, there are very important aspects we should know before assuming its harmlessness.
Although it is true that in safe doses fluoride helps remineralize tooth enamel, its systemic effect is not neutral.
In scientific literature, serious studies link it to alterations in thyroid function. This happens especially when it accumulates in the body from multiple sources (fluoridated water, toothpaste, processed foods). Evidence indicates that high concentrations can elevate TSH levels and reduce T3 and T4, interfering with hormonal balance.
But even more concerning: there is research linking chronic fluoride exposures to decreases in children's intelligence quotient (IQ), especially when exposure occurs in early developmental stages. A systematic review published in JAMA Pediatrics determined that elevated levels in drinking water were associated with an average IQ drop of 5 to 7 points.
And regulations allow it, yes, but with a major shortcoming: control over the actual amount we absorb daily is nonexistent. European regulation establishes a maximum concentration in toothpastes (usually between 1000 and 1500 ppm), but it does not take into account simultaneous exposure from multiple sources. Nor does it require long-term cumulative toxicity studies, or consider vulnerability during stages such as 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 product of daily use, which we accidentally ingest and which is used every day from childhood.
DEA (Diethanolamine): the foaming agent with hidden risks
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 perspective, it is far from harmless. One of the main problems with DEA is its ability to react with nitrosating agents present in 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 in rodents, an association with liver, kidney, and digestive tract tumors. Additionally, research published in journals such as Toxicology Letters and Environmental Health Perspectives has demonstrated that prolonged exposure to DEA can cause hormonal disruptions, especially at the level of 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 warning on the labeling. The European Union allows its restricted use, but does not prohibit the formation of nitrosamines, as long as certain impurity levels are not exceeded, which leaves an open window for chronic exposure through daily use. In addition, studies on dermal and mucosal absorption show that, although the compound has a 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 hygiene products is especially alarming due to direct and prolonged contact with the oral mucous membranes, which are highly permeable and represent a direct pathway to the circulatory system. And most concerning: it is an unnecessary ingredient from a functional point of view, as there are non-toxic natural alternatives with the same efficacy. In summary, the use of DEA represents an avoidable chemical risk, which remains present in 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 harm to health.
How did we get here?
When 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 making a comeback through the back door? Why do we continue to 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 little it may be—can have consequences that we don't yet fully understand.
I am not writing this to create fear, but to invite you to question. To look at labels with different eyes. To understand that "normal" is not always right. Because what is truly radical today is choosing what is healthy.
What if all this wasn't an exaggeration, but information they simply don't want you to have readily available? What if taking care of your health begins precisely with what you didn't think was a risk?
—Verónica, founder of Banbu
