Key Points
● Lesion Prevalence: Oral mucosal lesions were observed in 79% of examined nicotine pouch users and 89% of tobacco-derived snus users.
● Tissue Responses: Nicotine pouch users more often showed erythema and oral symptoms, while hyperkeratosis was more common among snus users.
● Product Factors: The findings raise questions about pH, flavouring, moisture, pouch materials and nicotine delivery, but no specific cause was established.
● Dental Outcomes: No higher prevalence of caries or periodontal disease was observed among nicotine pouch users.
● Evidence Limits: The study could not establish causality, long-term outcomes or an overall safety ranking between products or categories.
2Firsts,
July 27, 2026
A Swedish clinical study found oral mucosal lesions in 79% of examined young nicotine pouch users, compared with 89% of users of traditional tobacco-derived snus, adding to evidence that both product categories are associated with local tissue changes at the placement site.
Nicotine pouch users more often showed erythema and reported oral symptoms, while hyperkeratosis was more common among tobacco-derived snus users. The researchers did not observe a higher prevalence of caries or periodontal disease among participants who had used nicotine pouches for up to six years.
Nicotine pouches and traditional snus are both placed between the upper lip and gum to deliver nicotine, but the main difference is whether they contain tobacco. Traditional snus is made from processed tobacco and contains tobacco leaf or fibres, while nicotine pouches contain no tobacco material and are typically made with nicotine, plant-based fibres or cellulose, flavourings, sweeteners and pH adjusters. In everyday Swedish usage, both categories may be referred to as “snus,” but the study analysed nicotine pouches and tobacco-derived snus separately.
The study, published online on July 1, 2026, in the peer-reviewed journal Oral Diseases, was conducted by researchers from Public Dental Services in Stockholm County and the Department of Dental Medicine at Karolinska Institutet. It examined 272 people aged 18 to 30, including 126 nicotine pouch users, 63 users of tobacco-derived snus and 83 non-users.
The findings do not establish an overall safety ranking between nicotine pouches and tobacco-containing snus, and the study did not compare either category with smoking. They add a separate oral-health dimension to the assessment of products that do not involve combustion or contain tobacco leaf.
Lesions were common, but tissue responses differed
Lesions were observed at the habitual pouch placement site in 99 nicotine pouch users and 56 tobacco-derived snus users. Oral symptoms associated with use were reported by 44% of the nicotine pouch group and 35% of the tobacco-derived group. A burning sensation was the most frequently reported symptom in both groups.
The clinical findings included erythema, hyperkeratosis, oedema, surface etching and, in a small number of cases, ulceration. The study assessed clinical tissue changes and did not examine oral cancer or precancerous disease.
Hyperkeratosis, a thickening of the outer tissue layer, was recorded in 65% of nicotine pouch users and 79% of tobacco-derived snus users. Erythema was observed in 44% and 32%, respectively, while oedema was found in 15% of nicotine pouch users and 6% of tobacco-derived users. Two nicotine pouch users presented with ulcers; none were observed in the tobacco-derived group.
The researchers described nicotine pouch users as showing a broader range of mucosal responses, including hyperkeratosis, erythema, ulceration and lichenoid inflammation. Reactions among tobacco-derived snus users were more commonly dominated by hyperkeratosis.
Gingival recession at the usual placement site was observed in 44% of nicotine pouch users and 52% of tobacco-derived snus users. No recession was found at corresponding sites among non-users. The authors noted that gingival recession does not normally reverse spontaneously, although the cross-sectional study could not determine when it developed or whether pouch use caused each case.
Findings raise questions about formulation and design
The paper noted that nicotine pouches contain no tobacco leaf and generally contain substantially lower or non-quantifiable levels of several tobacco-related harmful constituents. The study nevertheless recorded local tissue reactions where pouches were regularly placed.
Nicotine pouch users reported a total of 40 flavour variants. Products may also differ in pH, nicotine concentration, moisture, pouch material, size and nicotine-release characteristics, while daily consumption, retention time and placement habits may affect local exposure.
The study did not test those variables independently. It found no significant association between the presence or severity of lesions and declared nicotine content, moisture level, wrapping material or pouch size.
Researchers observed a trend towards more pronounced tissue reactions among users of mint-flavoured products, but the association did not reach statistical significance. Among 84 users of five commonly reported mint-flavoured products, 38, or 45%, had lesions classified as grade 2 or 3 under the study’s severity scale.
The authors said differences in composition, pH, moisture, wrapping material and nicotine delivery could contribute to the varied tissue responses. Product-specific research would be needed to determine whether particular ingredients, formulations or pouch designs materially affect the likelihood or severity of oral lesions.
No higher prevalence of caries or periodontal disease observed
Caries was uncommon across all three groups. Most users also had periodontal probing depths below 4 millimetres in teeth adjacent to the pouch placement site, indicating no apparent relationship between use and periodontal pocket formation in those areas. Bleeding on probing was broadly similar between nicotine pouch and tobacco-derived snus users.
The findings were limited to a young population with no more than six years of use. Participants had a mean age of about 22, and the study recorded their clinical status at one point in time. It could not determine when lesions began, whether they would persist or regress after use stopped, or what outcomes might emerge after longer exposure.
The study also could not isolate the effects of individual ingredients and usage patterns. Its questionnaire had not been validated, and the researchers used two new grading systems developed for the study to classify tissue reaction and severity. Those tools will require assessment in other populations and studies.
How the study was conducted
The authors were Masoumeh Daneshian, Lars Fredriksson, Pia Skott and corresponding author Karin Garming Legert. They were affiliated with Public Dental Services in Stockholm County and the Department of Dental Medicine at Karolinska Institutet.
The study was funded by the Public Dental Service, and the authors declared no conflicts of interest. The journal also made its peer-review documents publicly available.
Participants were recruited during routine visits at nine public dental clinics across Stockholm County. Daily users were required to consume at least five pouches a day and to have used them for between three months and six years. Trained dentists examined the oral mucosa, gums and teeth, supported where necessary by intraoral photographs and existing radiographic information.
The participants were not drawn from a nationally representative sample. The nine clinics were selected from those where at least 10% of patients had previously reported daily snus use. The 79% finding therefore should not be treated as the prevalence among all young nicotine pouch users in Sweden or other markets.
The questions raised by the study have also featured in 2Firsts’ earlier reporting. In January 2026, 2Firsts interviewed Stingfree AB founder Bengt Wiberg about research into oral lesions, gum irritation and gingival recession associated with oral nicotine products.
The Swedish findings add clinical evidence on local mucosal effects while leaving the causes, long-term outcomes and differences between individual products unresolved.
2Firsts will continue to follow, publish and share the latest research findings related to the safety and risks of nicotine pouches. Researchers and institutions are welcome to contact Alan Zhao at alan@2firsts.com.
Cover image generated by AI.
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