A Retrospective Study Evaluating the Efficacy and Safety of Oral Semaglutide Compared to Injectables in Controlling Diabetes and Weight Reduction

Objective: To compare the efficacy, safety, weight reduction and treatment adherence of oral versus subcutaneous semaglutide in adults with uncontrolled T2DM and obesity. Methods: A multicenter retrospective cohort study was conducted between January 2023 and January 2024. Adult patients (≥18 years) with T2DM (HbA1c ≥ 7%) and obesity (BMI ≥ 30) who received either oral or subcutaneous semaglutide were included. Demographic, clinical, and biochemical variables including body weight, BMI, HbA1c, side effects, and adherence were extracted from electronic medical records. Adverse effects were categorized by severity. Comparative analyses between groups used Chi-square and Mann Whitney U tests, with p<0.05 considered statistically significant. Results: A total of 208 patients were included: 89 on oral semaglutide and 119 on subcutaneous semaglutide. Baseline demographics, including gender, age, and physical activity, were comparable between groups (all p>0.05). The severity of adverse effects predominantly gastrointestinal symptoms such as nausea, vomiting, constipation, and diarrhea did not differ significantly between groups (p=0.994). However, dizziness was significantly more frequent in the subcutaneous group (p = 0.04). Adherence was markedly higher with oral semaglutide (p<0.05), with cost identified as the primary barrier among oral users, while subcutaneous users more frequently cited side effects, forgetfulness, and limited weight loss. Weight reduction was comparable at 3 months (p=0.23), but significantly greater with oral semaglutide at 6, 9, and 12 months (all p<0.01). Conversely, HbA1c reduction favored subcutaneous semaglutide at 3 and 6 months (p=0.03 and 0.02), although baseline glycemic control was similar. Conclusions: This study demonstrates that while subcutaneous semaglutide may provide a faster early HbA1c decline, oral semaglutide offers superior long-term weight reduction and significantly better adherence, likely attributable to easier administration. Both formulations exhibited comparable safety profiles.