Standard toothpaste is not bad for you. The ingredients in commercially available toothpaste are regulated, well-studied, and safe for daily use when used as directed. That said, a few ingredients deserve a closer look, especially if you have sensitive gums, prone-to-canker-sores mouths, or young children in the house.
Fluoride: The Ingredient People Worry About Most
Fluoride is the most scrutinized ingredient in toothpaste, and also the most thoroughly validated. The recommended concentration in toothpaste is between 1,000 and 1,500 parts per million (ppm) for all age groups, a range the World Health Organization considers both effective and safe. At these levels, fluoride strengthens enamel and prevents cavities. It’s one of the reasons the WHO lists fluoride toothpaste as an essential medicine.
The concern most people have is about swallowing it. For adults, this is a non-issue. You’d need to ingest an enormous amount, around 5 mg of fluoride per kilogram of body weight, to reach a dose considered potentially toxic. For a 150-pound adult, that means eating roughly half a tube in one sitting. Toothpaste packaging is also capped at 276 mg of total fluoride per tube as an additional safety measure.
For children, the risk isn’t poisoning but cosmetic damage to developing teeth. Swallowing too much fluoride during the years when adult teeth are forming (roughly before age 6) can cause dental fluorosis: faint white spots or, in more severe cases, pitting on the enamel. The fix is simple. Children under 3 should use a rice-grain-sized smear of regular toothpaste. Kids aged 3 to 6 should use a pea-sized amount, about 0.25 grams. By age 6, the swallowing reflex is developed enough that accidental ingestion drops significantly. Low-fluoride “kids’ toothpaste” formulas (under 1,000 ppm) haven’t shown a meaningful cavity-prevention benefit, so the WHO recommends standard-strength toothpaste for all ages with the amount controlled instead.
SLS and Canker Sores
Sodium lauryl sulfate (SLS) is a foaming agent found in most toothpastes. It’s what creates that lather when you brush. Some people believe it triggers canker sores (recurrent aphthous ulcers), and you’ll find SLS-free toothpastes marketed to people who get them frequently.
The evidence here is surprisingly thin. A 2019 review found there wasn’t enough data to determine whether SLS-free toothpastes actually reduced ulcer frequency, duration, pain, or number of sores. A double-blind crossover study within that review reported no significant change in ulcer patterns when participants switched to SLS-free products. If you get frequent canker sores, trying an SLS-free toothpaste is low-risk and inexpensive, but don’t expect dramatic results based on current evidence. SLS itself is not harmful to the general population.
How Abrasives Can Wear Down Enamel
Every toothpaste contains mild abrasives to scrub plaque and surface stains off your teeth. The two most common are hydrated silica and calcium carbonate. These are measured on the Relative Dentin Abrasivity (RDA) scale, which rates how much wear a toothpaste causes on tooth structure. The FDA requires toothpastes to score below 200, and the American Dental Association sets its seal-of-acceptance limit at 250.
Here’s what the scale looks like in practice:
- 0 to 70 (low): Ideal for sensitive teeth and safe for daily use
- 71 to 100 (medium): Standard daily toothpaste range
- 101 to 150 (high): Can cause enamel wear over time with daily use
- 151 to 250 (harmful): Not recommended for long-term daily use
Whitening toothpastes tend to land higher on this scale. Laboratory research shows that silica-based abrasives are roughly twice as abrasive as calcium carbonate particles of the same size, and that larger, more irregularly shaped particles cause more wear. If you have sensitive teeth, receding gums, or exposed root surfaces, choosing a toothpaste with an RDA under 70 is a practical step. Most regular toothpastes from major brands fall comfortably in the low-to-medium range. The ones to watch are aggressive whitening formulas used every day for months.
Triclosan: A Concern That’s Mostly Resolved
Triclosan is an antibacterial chemical that was once added to some toothpastes, most notably Colgate Total. It raised concerns about potential hormonal effects and long-term health risks. The FDA ultimately pulled triclosan from consumer antiseptic products after manufacturers couldn’t provide conclusive proof it was both safe and effective. While no study has definitively shown triclosan causes cancer or birth defects in humans, the regulatory direction has been clear: it’s being phased out. You’d be hard-pressed to find it in toothpaste on store shelves today. If you’re using a very old tube, check the label, but this is largely a solved problem.
Artificial Sweeteners in Toothpaste
Toothpaste tastes sweet because it contains small amounts of artificial sweeteners, typically saccharin or occasionally aspartame. These replace sugar (which would obviously defeat the purpose) and are present in tiny quantities, far below what you’d consume from a diet soda.
Saccharin was flagged as a potential carcinogen in the 1970s after rat studies linked it to bladder cancer. More than 30 human studies since then have shown those rat results don’t apply to people. The National Toxicology Program removed saccharin from its list of potential carcinogens in 2000, and the warning label requirement was dropped. Aspartame has been reviewed in over 100 toxicity studies, and the FDA maintains it is safe at current consumption levels. Even if you swallowed your toothpaste (don’t), the amount of sweetener involved would be a fraction of what’s in a single packet of sugar substitute.
Hydroxyapatite: The Fluoride-Free Alternative
If you’re interested in avoiding fluoride entirely, hydroxyapatite toothpaste is the most evidence-backed alternative. Hydroxyapatite is a form of calcium that naturally makes up about 97% of your tooth enamel. Toothpastes containing 10% hydroxyapatite have shown comparable ability to remineralize early cavities and prevent enamel loss when tested against fluoride toothpaste in a randomized, double-blind crossover study. The two performed equally well, with no statistically significant difference in remineralization. Interestingly, hydroxyapatite produced a more even, homogenous repair pattern in the enamel compared to fluoride’s surface-layer approach.
These toothpastes are widely available in Japan (where they’ve been used for decades) and increasingly common in the U.S. and Europe. They cost more than standard fluoride toothpaste, typically $8 to $15 per tube. If your concern about toothpaste centers specifically on fluoride, this is a credible swap rather than going paste-free or using baking soda alone.
What Actually Matters
The biggest risk with toothpaste isn’t any single ingredient. It’s using an overly abrasive formula daily, brushing too hard with it, or (for young kids) swallowing too much fluoride during the years when permanent teeth are forming underground. A standard toothpaste with 1,000 to 1,500 ppm fluoride and an RDA under 100 is safe, effective, and appropriate for the vast majority of people. The real danger to your teeth isn’t toothpaste. It’s skipping it.