What Is Toothpaste Made Of? A Complete, Evidence-Based Ingredient Guide

Quick answer: Toothpaste is built from the same handful of ingredient categories no matter what the label promises: water, an abrasive, a surfactant (usually SLS), a humectant, a thickener, flavoring, a preservative, and often fluoride or an antibacterial agent. Labels like "SLS-free," "tartar control," "sensitive," or "natural" describe which specific ingredient fills each role, not a different formula altogether.

If you've ever stood in the toothpaste aisle wondering what actually separates these products, you're asking the right question. Here's what's really in the tube.

What is toothpaste actually made of?

Every toothpaste, regardless of brand or marketing claim, is built from roughly eight functional ingredient categories: water, an abrasive, a surfactant, a humectant, a thickener, flavoring, a preservative, and (in many formulas) an active ingredient like fluoride or an antibacterial agent. Understanding these categories is the fastest way to compare products, because the front-of-tube claim tells you almost nothing on its own.

Why does toothpaste contain water?

Toothpaste is 20 to 42 percent water. Water keeps the paste from drying into a hard, unusable block and helps the other ingredients blend into a spreadable texture.

What is the abrasive in toothpaste, and can it hurt my teeth?

Most commercial toothpaste is at least 50 percent abrasive, using ingredients like hydrated silica or calcium carbonate to physically loosen plaque and surface stains. Baking soda (sodium bicarbonate) is a gentler, effective alternative.

Abrasives work mechanically, buffing the tooth surface rather than dissolving anything chemically. That's useful for stain removal, but if you already deal with sensitive teeth, thinning enamel, or receding gums, a highly abrasive formula can make sensitivity worse over time. Baking soda has the added benefit of helping neutralize acid in the mouth and balancing salivary pH. If you're not sure how abrasive your current toothpaste is, ask your dentist about its RDA (relative dentin abrasivity) score rather than guessing from the label.

Do I need fluoride in my toothpaste?

US toothpaste typically contains 1,000 to 1,100 ppm of fluoride, from one of three sources: sodium fluoride (the most common), stannous fluoride, or sodium monofluorophosphate. Fluoride is effective at strengthening enamel for many people, and it's the right choice for a lot of households. Others prefer to avoid it, whether for young children who may swallow toothpaste or for personal reasons. Fluoride-free alternatives like xylitol, baking soda, and dicalcium phosphate support oral health through different mechanisms rather than replacing fluoride's exact function.

What is SLS, and why do some toothpastes leave it out?

Sodium lauryl sulfate (SLS) is the detergent that makes most toothpaste foam. It's effective at helping lift plaque, but its surface-active chemistry can also strip the protective mucin layer lining the mouth, which is part of why some people notice canker sores or stinging after brushing.

The clinical evidence here is genuinely mixed, and it's worth saying so plainly rather than picking the version that sounds better. A crossover clinical trial found a statistically significant drop in recurrent canker sores during two months of SLS-free toothpaste use compared to two months of SLS-containing toothpaste.¹ A later review points to a likely mechanism: SLS can strip away the mouth's protective mucin layer, reducing the tissue's natural resistance.² But not every study agrees. A separate double-blind crossover trial concluded that switching to an SLS-free toothpaste had no significant effect on ulcer patterns in patients with recurrent oral ulceration.³

Translation: if you get frequent canker sores, switching to an SLS-free toothpaste is a reasonable, low-risk thing to try, but it isn't a guaranteed fix for everyone. Sores that are frequent, large, or slow to heal deserve a dentist's look regardless of toothpaste.

Should toothpaste contain antibacterial ingredients like triclosan?

Triclosan is added to some toothpaste specifically to help manage gingivitis, and the FDA's own review found real evidence for that narrow use: in 1997, the agency reviewed effectiveness data on triclosan in a leading toothpaste brand and confirmed it helped prevent gingivitis.⁴ At the same time, the FDA has noted that other studies raise the possibility that triclosan exposure contributes to antibiotic-resistant bacteria.⁴

It's a nuance worth knowing: when the FDA banned triclosan from over-the-counter wash products in 2016 over resistance concerns, toothpaste wasn't included in that ban.⁵ So it remains legal and, for active gum disease, can be genuinely useful short term. Long-term daily use in someone without active gum disease is where the resistance concern outweighs the benefit for most people. If your dentist has you on a triclosan toothpaste, it's worth asking how long to stay on it.

Why does toothpaste taste minty, and can that cause problems?

Mint, peppermint, spearmint, and wintergreen are the most common toothpaste flavors. Menthol works by activating a nerve receptor called TRPM8, which signals "cold" to your brain, that's the tingling sensation you feel after brushing. In a sensitive mouth, especially one dealing with dry mouth, that same signal can register as burning instead of freshness. Natural brands often swap mint for essential oils like anise, fennel, or lavender, but these botanicals are also common allergens and can irritate oral tissue, so "natural flavor" isn't automatically the gentler choice.

What does "remineralizing" toothpaste actually do?

Some toothpaste is formulated to support the tooth's outer enamel surface using ingredients like calcium phosphate. This works alongside brushing and flossing, not as a replacement for them, and results (if any) show up over weeks of consistent use, not overnight.

What are humectants, and is xylitol really better than glycerin?

Humectants keep toothpaste from drying out and give it texture. Glycerin, sorbitol, and water are the most common. Xylitol stands out because it does more than hold moisture: research shows it promotes remineralization by increasing salivary flow, and it inhibits bacterial growth in plaque.⁶

Here's the honest caveat: despite those favorable properties, researchers still describe the clinical evidence for xylitol as a cavity-prevention agent as controversial.⁶ A Cochrane systematic review of the toothpaste-specific studies noted it's unclear what a 10 percent xylitol toothpaste equates to as a daily dose, since that depends heavily on how much toothpaste is actually used.⁷ Most of the strongest anti-cavity evidence for xylitol comes from gum and lozenges used several times a day, not toothpaste used twice. That doesn't erase xylitol's saliva-boosting benefit for dry mouth, it just means "prevents cavities" is a stronger claim than the toothpaste research alone supports.

What do thickeners do, and are they safe if I have celiac disease or a gluten sensitivity?

Carrageenan, cellulose gum, guar gum, and xanthan gum are common toothpaste thickeners. Xanthan gum is a safe, gluten-free option for people avoiding gluten. Irritation from these gums is rare and, when it happens, is usually mild bloating or gas, and that typically only occurs from ingesting much larger amounts than what's in a normal brushing. People with a soy or corn allergy may want to check the specific source of their gum. (The respiratory risk sometimes mentioned with xanthan gum applies to inhaling raw manufacturing powder, not to using finished toothpaste.)

Why does toothpaste need preservatives, and are they safe?

Preservatives stop microorganisms from growing in the tube. Sodium benzoate, methylparaben, and ethylparaben are common choices, and of the three, sodium benzoate has the mildest safety profile. Some "natural" formulas use citric acid instead; citric acid is generally well tolerated at toothpaste-level amounts, with stomach upset only reported at doses far higher than anyone would swallow from brushing.

Are toothpaste sweeteners safe?

Saccharin, stevia, and xylitol are the most common sweeteners, added mainly to offset the bitter taste of SLS. Xylitol does double duty here, sweetening the paste while also supporting saliva flow (see above).

Why is my toothpaste white, and should I worry about dyes?

Titanium dioxide is the ingredient typically responsible for toothpaste's white color, and artificial dyes show up in some commercial formulas for visual appeal. Neither is necessary for the paste to work. If you prefer a simpler ingredient list, look for a formula without added dyes.

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Toothpaste ingredients at a glance

Category	Common ingredients	What it does	What to watch for
Water	Purified water	Prevents drying out	Not a concern
Abrasive	Silica, calcium carbonate, baking soda	Physically removes plaque and stains	High abrasivity can worsen sensitivity
Active (cavity)	Fluoride, or xylitol/baking soda/dicalcium phosphate	Strengthens or supports enamel	Fluoride-free ≠ ineffective, just a different mechanism
Surfactant	Sodium lauryl sulfate (SLS)	Creates foam, helps lift plaque	Linked to canker sore flare-ups in some studies
Antibacterial	Triclosan	Reduces gingivitis-causing bacteria	Long-term use linked to antibiotic resistance concerns
Flavor	Mint, peppermint, essential oils	Taste and sensation	Essential oils can trigger allergies
Humectant	Glycerin, sorbitol, xylitol	Retains moisture, texture	Xylitol adds saliva/dry-mouth benefit
Thickener	Xanthan gum, carrageenan, guar gum	Gives paste its consistency	Xanthan gum is gluten-free; check for soy/corn source
Preservative	Sodium benzoate, parabens, citric acid	Prevents microbial growth	Sodium benzoate is the mildest of the three
Sweetener	Saccharin, stevia, xylitol	Masks bitterness of SLS	Xylitol doubles as an active ingredient
Color	Titanium dioxide, dyes	Whitens or colors the paste	Not functionally necessary

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Frequently asked questions

Is SLS-free toothpaste better if I get canker sores?
It's worth trying. Clinical evidence is mixed, some studies show fewer ulcers with SLS-free formulas, others show no difference. Frequent or severe sores should still be evaluated by a dentist.

Is fluoride-free toothpaste as effective as fluoride toothpaste?
Fluoride-free toothpaste works through different mechanisms (like baking soda's acid-neutralizing effect and xylitol's saliva-boosting effect) rather than fluoride's remineralization pathway. It's a different approach, not an inferior one, and the right choice depends on your personal preference and risk factors, which a dentist can help you weigh.

What ingredient makes toothpaste foam?
Sodium lauryl sulfate (SLS) is responsible for foaming in most conventional toothpaste. SLS-free formulas use gentler surfactants and simply produce less foam, which doesn't affect cleaning power.

Is "natural" toothpaste automatically gentler or safer?
Not necessarily. Natural formulas often substitute essential oils (like anise, fennel, or lavender) for mint, and those botanicals are common allergens and irritants in their own right. "Natural" describes the ingredient source, not automatically its gentleness.

How long should someone use a triclosan (antibacterial) toothpaste?
Only your dentist can say for your situation, but the general pattern in the research is: short-term use for active gum disease shows real benefit, while indefinite daily use for people without gum disease carries a documented antibiotic-resistance concern with less clear upside.

Is xylitol toothpaste safe around pets?
This one matters: xylitol is safe for humans but is highly toxic to dogs, even in small amounts, and can cause a rapid, dangerous drop in blood sugar. Keep any xylitol-containing toothpaste (and dental floss, gum, or candy) somewhere your dog cannot reach it, and call a vet immediately if you suspect ingestion.

What does "non-abrasive" toothpaste mean?
It means the paste relies on a gentler cleaning ingredient (often baking soda at a controlled concentration) instead of harder abrasives like silica, which is generally a better fit for people with sensitive teeth or thinning enamel.

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For anyone choosing between formulas, the ingredient list tells you far more than the front-of-tube claim does. If you're looking for a fluoride-free option, Cleure's toothpaste is formulated without SLS or antibacterial agents and uses baking soda, xylitol, and dicalcium phosphate to support a sensitive mouth. As with any toothpaste switch, patch test if you have known sensitivities and give it a few weeks before judging results.

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References

1. Herlofson BB, Barkvoll P. Sodium lauryl sulfate and recurrent aphthous ulcers: a preliminary study. PubMed.
2. Alli BY, et al. The effectiveness of dentifrices without and with sodium lauryl sulfate on plaque, gingivitis and gingival abrasion. PMC.
3. Healy CM, et al. The effect of a sodium lauryl sulfate-free dentifrice on patients with recurrent oral ulceration. PubMed.
4. U.S. Food and Drug Administration. 5 Things to Know About Triclosan.
5. Ribado JV, et al. Household triclosan and triclocarban effects on the infant and maternal microbiome. PMC.
6. Ly KA, et al. Tooth-surface-specific effects of xylitol: randomized trial results. PMC.
7. Riley P, et al. Xylitol-containing products for preventing dental caries in children and adults. Cochrane Database, PMC.