Transcutaneous Auricular Vagus Nerve Stimulation for Poor Weight-Loss Response to Incretin Receptor Agonists

This is a single-center, randomized, participant-blinded, sham-controlled trial designed to evaluate the adjunctive effect of transcutaneous auricular vagus nerve stimulation (taVNS) in overweight or obese patients who show a suboptimal weight-loss response to incretin receptor agonist therapy. A total of 24 participants will be randomly assigned to receive either taVNS plus tirzepatide 5 mg or sham stimulation plus tirzepatide 5 mg for 12 weeks. The primary objective is to compare the percent change in body weight from baseline to week 12 between the two groups.

Inclusion Criteria: 1. Individuals with obesity, or overweight accompanied by at least one weight-related comorbidity (e.g., hypertension or fatty liver disease), who have been receiving tirzepatide therapy for at least 12 weeks and have achieved ≤10% weight loss during treatment; 2. Willingness to provide written informed consent. Exclusion Criteria: 1. Presence of diseases that may substantially affect body weight homeostasis, including Cushing's syndrome, uncontrolled thyroid disease (thyroid-stimulating hormone \>6.0 mIU/L or \