Karolinska Institutet and Public Dental Services Shatter the Myth: Nicotine Pouches Cause More Aggressive Oral Lesions Than Tobacco Snus

A comprehensive clinical study from Karolinska Institutet and the Public Dental Services in Stockholm definitively shatters the myth that tobacco-free nicotine pouches are gentle on the mouth. The study reveals the alarming result that 79 percent of young users suffer from injuries and wounds in the oral mucosa—despite the participants’ mean age being as low as 22 years.

How Do Nicotine Pouches Affect Your Oral Health?

The scientific study, published in the international journal Oral Diseases, evaluated young adults with a mean age of just 22 years. The data-driven results demonstrate that the chemical and biological impact of nicotine pouches is significantly more aggressive than the industry previously suggested.

Researchers concluded that nicotine itself is not what damages the gums. Instead, it is the combination of high concentrations of flavoring agents (especially mint and menthol) and the necessary chemicals used for pH regulation. A high and alkaline pH level is an absolute requirement for the soft tissues in the oral cavity to absorb nicotine efficiently, but this chemical composition simultaneously causes irritation and tissue damage to the mucosa.

Key Findings of the Study:

• Receding Gums (Gingival recession): Close to 50 percent (every second user) aged 18–30 suffered from permanent gum recession at the exact site where the pouch is placed.

• Comparison with Non-Users: Among those who do not use any nicotine products at all, the prevalence of receding gums was only 6 percent.

• Irreversible Damage: Gums that have receded never grow back, leading to exposed tooth necks, chronic sensitivity, and a long-term risk of tooth loss.

• Shorter Time but Worse Damage: Nicotine pouch users keep the pouch in their mouth for an average of 11 to 30 minutes, compared to traditional tobacco snus users who often keep it for up to an hour. Despite the nicotine pouch spending half as much time under the lip , it causes equal or more severe tissue damage due to its aggressive chemical composition.

• Aggressive Inflammation vs. “Snus Callus”: While traditional tobacco snus typically causes a localized hardening of the mucosa (hyperkeratosis) as a biological protective response , nicotine pouches prompt a significantly more aggressive biological reaction. Users more frequently experience severe redness (erythema), inflamed salivary glands, and open wounds (ulcerations) that spread far beyond the placement of the pouch.

Growing International Concern and the French Ban

The Scandinavian research points to a clear scientific consensus. The results are backed up by a previous Norwegian study on teenagers where over 79 percent exhibited snus lesions , as well as research led by Professor Gita Gale at the University of Gothenburg. Gale’s research shows that nicotine pouches trigger chronic inflammation that remains difficult to heal even after the user stops using them.

These medical discoveries have already led to major international political consequences. Citing these extensive oral health problems, the French government decided to completely ban nicotine pouches. However, this type of ban has faced criticism for being deeply unscientific, as lethal smoking remains completely legal in the country—despite the fact that smoking is proven to both shorten life expectancy and severely degrade oral health on a completely different level than smoke-free alternatives.

New Technology Proven to Reduce the Occurrence and Severity of Injuries

Since the damage from nicotine pouches is proven to be chemical , it can be addressed through altered product design. Here, a new Swedish barrier technology (Protex®) demonstrates a proven way to reduce the occurrence and degree of injuries to the oral mucosa.

An independent international clinical study published in Acta Odontologica Scandinavica shows a significantly reduced occurrence and severity of injuries. By integrating an ultra-thin protective barrier on the gum-facing side of the pouch—the patented Swedish technology Protex®—direct chemical contact between the contents of the nicotine pouch and the oral mucosa is blocked. Flavor and nicotine are instead delivered efficiently through the other side of the pouch.

It is worth noting that the clinical study on Stingfree pouches utilized products featuring mint and menthol flavors. Given that the new independent KI/Public Dental Services study proves this specific flavor profile is extra aggressive and linked to more pronounced tissue changes, the strong clinical results achieved by the barrier technology despite using the most challenging flavor profile make the findings from the Stingfree study even more remarkable.

When the technology was clinically tested on active pouch-using Swedish dentists, the results after five weeks of use showed very high efficiency:

• High Scientific Certainty (p=0.0002): The study proves with 99.98 percent statistical certainty that the demonstrated reduction in injuries was due to the protective barrier, and not to chance.

• 90% Reduced Perceived Irritation: The participating dentists’ subjective experience was that pouches with the Protex® barrier reduced perceived gum irritation by 90 percent compared to their baseline before the test began.

• Clinically Proven Healing and Reduction of Inflammation: The study showed extensive healing of the oral mucosa in participants with moderate to severe snus lesions (Grade 3–4 on the Axell scale) , as well as a highly notable reduction in gum inflammation (gingivitis).

Comment from Bengt Wiberg, Founder and Chairman of Stingfree AB: “Oral damage should not be the price people are forced to pay for choosing to quit smoking. The fact that 8 out of 10 young users are affected, despite the products remaining in the mouth for a shorter duration, proves that today’s pouches have a pure design flaw. Now that heavy international expertise shows there is proven technology that reduces direct contact with the contents of the portion pouches, the industry simply can no longer turn a blind eye to consumer safety.”

The Protex® technology is currently patent-approved in the US and in 36 European countries.

Clinical Resources and Sources:

• The KI/Public Dental Services Study (2026): ”Oral Lesions and Dental Status in Individuals Using Oral Tobacco-Free Nicotine Pouches” – Oral Diseases, Wiley.

• The International Clinical Barrier Study (2025): ”Self-reported oral health outcomes after switching to a novel nicotine pouch technology: a pilot study” – La Rosa et al., Acta Odontologica Scandinavica.

• University of Gothenburg: Professor Gita Gale’s research on long-term inflammation from nicotine pouches.