This Phase 3 study evaluates the efficacy and safety of once-weekly subcutaneous tirzepatide (a dual GIP and GLP-1 receptor agonist) at 5 mg, 10 mg, or 15 mg versus placebo, each used with a reduced-calorie diet and increased physical activity, in adults without type 2 diabetes who have obesity or are overweight with weight-related comorbidities. The primary efficacy assessment is at Week 72. Participants with prediabetes at randomization may continue in an additional long-term treatment period to assess progression to type 2 diabetes and longer-term weight outcomes.
BMI ≥30 kg/m², OR BMI ≥27 kg/m² with ≥1 weight-related comorbidity (e.g., hypertension, dyslipidemia, obstructive sleep apnea, cardiovascular disease)
History of at least one unsuccessful dietary effort to lose weight (self-reported)
Investigator judges participant capable and willing to self-inject (or have assistance), follow lifestyle advice, maintain a diary, and complete questionnaires
Age ≥18 years
Type 1 or type 2 diabetes, history of ketoacidosis/hyperosmolar state, or screening labs diagnostic of diabetes
Recent significant weight change (>5 kg within 3 months prior to screening)
Prior/planned bariatric surgery; recent/ongoing endoscopic or device-based obesity therapies
Severe renal impairment (eGFR <30 mL/min/1.73 m²)