Efficacy of Tirzepatide for Weight Management in Patients With Suboptimal Weight Loss After Bariatric Surgery: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Many people who have bariatric (weight-loss) surgery do not lose as much weight as expected, or they regain weight over time. This study will test whether a medicine called tirzepatide can help these patients lose more weight and improve their overall health. Participants who had bariatric surgery at least one year ago and still have obesity with insufficient weight loss will be randomly assigned, like a coin flip, to receive either tirzepatide or a placebo (an inactive injection that looks the same). Neither participants nor study staff will know who is receiving which treatment. Participants will inject the study medicine or placebo once a week for 52 weeks, starting at a low dose that is gradually increased. During the study, researchers will measure body weight, waist size, blood pressure, and blood tests related to metabolism and inflammation. Participants will also answer questionnaires about their quality of life. The main goal is to find out whether tirzepatide leads to greater weight loss than placebo after one year of treatment.

Inclusion Criteria: 1. Adults (male or female) aged ≥18 years. 2. History of bariatric surgery (Roux-en-Y gastric bypass or sleeve gastrectomy) performed ≥12 months before enrollment. 3. Current BMI ≥30 kg/m². 4. Evidence of suboptimal weight loss, defined as percentage total weight loss (%TWL) since surgery of less than 25% (defined as the percentage of weight loss comparing current body weight with body weight before surgery). 5. Absence of recent weight loss (defined as \