Oral health effects of nicotine pouches in snus users: clinical and immunological findings

Objectives Changes in the oral mucosa are characteristic of snus-induced lesions (SILs), typically occurring at the site of pouch placement. These lesions are reversible after cessation. This study evaluated the effects of two non-tobacco-based nicotine pouches (ZYN ® Dry and ZYN ® Moist) on SIL severity, salivary cytokines, epithelial thickness, and inflammatory cell presence after 28 days of exclusive use. Materials and methods In this open-label, randomized longitudinal study, 45 daily snus users were assigned to either the dry formulation ( n = 23) or the moist formulation ( n = 22) for four weeks. Clinical assessments were performed at baseline, day 14, and day 28. Lesions were graded on a four-point scale. Biopsies and saliva samples were collected at baseline and day 28. Results Both groups showed significant improvement in lesion severity ( p < 0.0001). No significant changes were observed in epithelial thickness, inflammatory cell infiltration, total protein levels, IL-1β, TNF-α, or MCP-1. IL-8 levels increased significantly in the dry formulation group ( p < 0.01). Conclusions Switching to nicotine pouches improved SILs without major changes in the inflammatory markers assessed. Clinical relevance Nicotine pouches were associated with improvement of snus-induced lesions in this study population. Trial registration ISRCTN13243849, registered 01/09/2022.