Allergen immunotherapy, particularly sublingual immunotherapy (SLIT), has emerged as a promising treatment for allergic rhinitis. However, patient adherence to SLIT remains a significant challenge, often compromising therapeutic outcomes. While various studies have explored the efficacy of SLIT, few have focused on real-world adherence barriers and patient-reported outcome measures such as Visual Analogue Scale (VAS) scores across treatment phases. This retrospective chart review aims to investigate the barriers to adherence in patients undergoing SLIT for allergic rhinitis and analyse changes in VAS scores after each administered dose. Medical records of patients diagnosed with allergic rhinitis and treated with SLIT over a defined period will be reviewed. Data, including demographics, clinical history, adherence patterns, missed doses, reasons for non-compliance, and VAS scores following each dose, will be collected and analysed. The study seeks to identify common factors contributing to poor adherence and evaluate trends in symptom improvement based on VAS scores. Insights gained may inform strategies to improve compliance and optimize SLIT outcomes in routine clinical practice.