We unpick the truth behind the chemicals in your daily toothpaste.

An Unloved Staple

For decades, brushing our teeth has been a daily ritual — an almost mechanical act carried out once in the morning and once before bed. While few would claim to love brushing, most of us feel uneasy heading out the door or hitting the pillow without that minty-fresh cleanse.

Yet this everyday staple often goes unnoticed: we rarely question the ingredients that compose our toothpaste. Even dentists, our go-to experts, may spend as little as half an hour studying oral care products in their formal training. So why have we all become numb to a product we use so regularly? Are we ignoring ingredients that might be harmful to us? And, most importantly, is there any real innovation left to explore in toothpaste?

Before answering these questions, it helps to look at how toothpaste came to be — and why its main job hasn’t changed much for a century.

A Quick History of Toothpaste

Throughout history, humans have used all sorts of mixtures to clean their teeth:

· Ancient Egyptians used rock salt, mint, iris flowers, and pepper.

· Greeks and Romans favoured crushed bones and oyster shells.

· Chinese cultures blended salt, ginseng, and mint.

By the 1800s, chalk and soap found their way into dental powders, and the first collapsible tubes of toothpaste were introduced in 1892. Fast-forward to 1914, and you’ll find the most significant game-changer: fluoride.

Fluoride — Let’s talk about it

Most toothpastes use Fluoride except when explicitly expressed otherwise. A dentist once told me:

“Fluoride is 98% of what matters in a toothpaste. The remaining 2% are just desperate attempts at product differentiation.”

It sounds hyperbolic, but there’s some truth to it. Toothpaste primarily serves three functions:

1. Remineralisation and Repair

Our teeth face daily wear from acids and plaque, weakening enamel. Toothpaste (traditionally through fluoride) accelerates remineralisation, restoring strength faster than saliva alone can manage.

2. Enhanced Cleaning

Plaque forms throughout the day, and brushing is the mechanical action that removes much of it. Abrasives in toothpaste can help lift stains and polish the tooth’s surface — in moderation.

3. Reducing Bad Bacteria in the Mouth

With over 700 species of bacteria, the oral microbiome is incredibly complex. Traditional approaches use antimicrobials to destroy bacteria; newer philosophies harness prebiotics to support beneficial bacteria.

Ask most dentists about toothpaste’s real value, and they’ll say one word: fluoride. It’s still considered the most proven defence against tooth decay, thanks to its ability to bond with and strengthen enamel. So, is that the entire story? Not quite.

Internet Scaremongering or Right to Re-think?

Fluorosis (Overexposure Risks)

Excess fluoride during tooth development (primarily in children) can cause dental fluorosis, leading to white spots or streaks on teeth.

In severe cases, it can cause skeletal fluorosis, affecting bones and joints. This, however, is much more common from over exposure through accidentally over-fluoridated water than toothpaste.

Neurotoxicity Concerns

Some studies suggest high fluoride exposure could be linked to lower IQ in children. Research from the National Toxicology Program (NTP) and Harvard University indicates potential neurodevelopmental effects, though the exact threshold and risk factors remain debated. These particular studies have been largely criticised due to concerns about the limited sample size, and overfitting of trends over low-quality data.

Hormonal & Thyroid Impact

Fluoride has been linked to thyroid dysfunction, particularly hypothyroidism, as it can interfere with iodine absorption. Some studies suggest fluoride exposure correlates with increased thyroid disorders.

Cancer Risk Debate

Some animal studies have raised concerns about a possible link between fluoride and osteosarcoma (bone cancer), though human studies remain inconclusive.

The American Cancer Society and other regulatory bodies have not found conclusive evidence to confirm fluoride as a carcinogen.

Toxicity at High Doses

Fluoride is toxic in large amounts, leading to nausea, vomiting, and even acute poisoning if ingested in very high concentrations. This is why toothpaste carries warnings about swallowing, and is limited to 1500ppm (roughly 1.5%).

Some consumers prefer to avoid fluoride entirely, but going fluoride-free can leave you vulnerable to dental decay.

The Hidden Truths of Modern Toothpastes

If fluoride is “98% of what matters,” what about that other 2%? For many decades, toothpaste makers have added a cocktail of additional ingredients — often to cut costs, improve appearance, or enhance flavour. Worryingly, toothpastes in many regions are regulated more like cosmetics than ingestible products, which means ingredients banned from certain foods could still appear in the toothpaste that sits on our bathroom sink.

Below are some potentially harmful or controversial substances found in many modern toothpastes. We’ll show which of the top 20 most popular toothpastes contain them — and why you might consider avoiding them.

1) Titanium Dioxide

A small selection of toothpastes that contain Titanium Dioxide

Why It’s Used

Colouring Agent: Gives toothpaste that bright, appealing white look.

The Concern

In 2022, the EU banned Titanium Dioxide in food due to its genotoxicity — raising concerns it may alter DNA and pose a cancer risk.

Toothpaste brands still use it because, as a cosmetic, it hasn’t (yet) been similarly restricted in many places.

What to Watch For

If you’re worried about exposure, you may want to avoid or limit products using titanium dioxide until regulatory agencies tighten standards.

2) Sodium Lauryl Sulfate (SLS)

A selection of toothpastes that contain Sodium Lauryl Sulfate

Why It’s Used

Foaming Agent: A cheap detergent that creates that familiar foamy feel.

The Concern

SLS can irritate sensitive oral tissues (cheeks, lips, gums) and may cause dry mouth, peeling skin, or discomfort for some users.

Gentler alternatives exist and can provide a similar cleaning effect without risking irritation.

What to Watch For

Consider switching to an SLS-free or gentler surfactant toothpaste if you experience chronic mouth dryness or irritation.

3) Harsh Abrasives (Charcoal & Other “Whitening” Agents)

Toothpastes containing higher abrasive grades of Hydrated Silica or other abrasive compounds. There are many more - think charcoal toothpaste or similar.

Why They’re Used

Stain Removal & “Whitening”: Abrasives lift surface stains and promise a quick brightening effect.

The Concern

Overly abrasive formulas can damage enamel over time, revealing more of the yellow dentin beneath and eventually increasing tooth sensitivity.

Charcoal toothpastes, in particular, have been criticised for scrubbing enamel too aggressively.

What to Watch For

Check a toothpaste’s Relative Dentin Abrasivity (RDA) if available. Dentists generally don’t recommend highly abrasive formulas for daily use.

4) Copolymers, Proloxymers, and PEGs

Toothpastes that contain Copolymers, Proloxymers or PEGs, though many more exist.

Why They’re Used

Texture & Stability: Sometimes colloquially called “liquid plastics”, PEGs (polyethylene glycols), Copolymers and other polymers make toothpaste smooth and help different ingredients blend evenly. Some can form a “film” to enhance whitening effects.

The Concern

Potential issues with contamination, unproven bioaccumulation, and the possibility of chemical reactions with other substances.

Data is still emerging, but it is recommendable to avoid them as a precaution.

What to Watch For

If you’re concerned, look for toothpastes labeled PEG-free or “polymer-free.” There are natural or plant-based thickening agents that can replace these compounds.

5) PAP Acids

The products that contain PAP acids (Phthalimidoperoxycaproic acid):

Why It’s Used

Whitening: PAP can whiten teeth below the surface without using peroxide.

The Concern

PAP can potentially soften enamel, and when combined with mechanical brushing, it risks wearing away that protective outer layer.

Long-term studies are still emerging, so many dentists remain cautious until further research clarifies safety profiles.

What to Watch For

If whitening is your goal, consider static whitening trays or consult a professional. Avoid regularly brushing with strong bleaching agents that could harm enamel. Occasionally using Peroxide whitening products, which in many regions (like the UK and Europe) can only be administered by dentists, is preferable to using PAP.

Regulatory Landscape and Industry Opposition

Despite the questionable nature of some of these ingredients, major toothpaste manufacturers often push back against tighter regulations. In many countries, toothpastes are simply classified as cosmetics, making it easier to continue using additives that might be banned or restricted in foods. The industry claims that many of these substances are either used in minuscule amounts or are safe under normal brushing conditions.

However, a growing number of independent experts and consumer advocates argue that daily oral exposure warrants closer scrutiny than typical cosmetic regulations.

So, Back to Fluoride… and the Step-Change of Hydroxyapatite

If fluoride was the big star for over a century, the next major breakthrough may be hydroxyapatite (HAP) — the same mineral that forms most of our teeth and bones. Discovered by NASA scientists in the 1970s to combat bone density loss in astronauts, hydroxyapatite has since shown promising results in remineralising teeth. Some of the benefits include:

Biocompatibility:

Because teeth are made of HAP, synthetic nano-hydroxyapatite can fill micro-lesions and strengthen enamel. This biocompatibility enables HAP to integrate into damaged enamel prisms, into the tooth subsurface, and increase the toughness of enamel. 

Reducing Sensitivity & Adding Shine:

Unlike harsh abrasives, HAP can deposit new mineral layers onto the tooth surface, helping fight sensitivity and subtly whitening teeth by adding a natural, enamel-like coating.

Some so-called “natural” brands have added a trace amount of HAP — often too little to rival fluoride, often 1.5% or less. However, newer formulations using higher concentrations (up to 12%) of nano and micro hydroxyapatite have proven that toothpaste can shift away from fluoride dependence while still effectively strengthening teeth.

Some so-called “natural” brands have added a trace amount of HAP — often too little to rival fluoride, often 1.5% or less. However, newer formulations using higher concentrations (up to 12%) of nano and micro hydroxyapatite have proven that toothpaste can shift away from fluoride dependence while still effectively strengthening teeth. These advances suggest there is room to reinvent toothpaste — to create a product free of unnecessary chemicals but still protecting against decay.

Higher Remineralisation, Increase in Hardness and Stiffness of Teeth:

A recent study by renowned Dr. Andrei Ionescu and commissioned by Nura as part of their research into effective formulations has found that HAP can be highly effective, if used correctly. When used in optimal percentages, the combination of nano-HAP and micro-HAP outperforms Fluoride. It even outperforms formulations with HAP and Fluoride, as the two components react and calcify, lowering the efficacy.

The staggering results showed that the formulation can outperform a leading Fluoride formula from the world’s #1 brand by as much as 2x when it comes to remineralisation, hardness and stiffness of teeth. You can get early access to their formulation right now, which will launch in May 2025 in the UK, by joining their waitlist.

Rethinking an Everyday Ritual

Toothpaste isn’t something we typically adore, but it’s a routine so ingrained in our day-to-day lives that we almost forget to question it. The ingredient list mentioned above in many mainstream brands can be worrisome — especially given how easily oral tissues can absorb certain chemicals.

Key Takeaways

1. Read Labels: Familiarise yourself with ingredients like titanium dioxide, SLS, harsh abrasives, copolymers/PEGs, and PAP acids — particularly if you have sensitive teeth, gum issues, or other concerns.

2. Consider Alternatives: Look for toothpastes with gentler or more natural surfactants, lower abrasivity and fewer synthetic additives.

3. Explore Hydroxyapatite: If you want to go fluoride-free, seek high-quality formulations containing enough nano-hydroxyapatite and micro-hydroxyapatite (must be at least 10%) to genuinely protect and repair enamel. If a brand doesn’t state the percentage of materials used, be skeptical.

4. Stay Informed: As research evolves, so do regulations. Keep an eye out for new studies on the safety of titanium dioxide, SLS, and other additives.

Yes, toothpaste can still be innovated. We’re witnessing a potential paradigm shift — away from questionable chemical cocktails and toward formulas that genuinely protect, strengthen, and improve the health of our teeth. After a century of the same old thing, it’s a change many would call long overdue.