To investigate the efficacy and safety of beinaglutide as an adjunct to lifestyle intervention among non-diabetic Chinese individuals with overweight or obesity.This multicentre, randomized, double-blind, placebo-controlled trial (ChiCTR1900023428) included 427 Chinese adults with a body mass index of 28 kg/m2 or higher (obesity) or 24-27.9 kg/m2 (overweight) with weight-related complications. Patients were randomized in a 2:1 ratio to receive 0.2 mg of beinaglutide (subcutaneous) thrice daily or placebo for 16 weeks. Co-primary endpoints were body weight change and the proportion of patients with a weight reduction of 5% or more.Mean body weight change from baseline to week 16 was -6.0% and -2.4% in the beinaglutide (n = 282) and placebo (n = 138) groups, respectively; the mixed model repeated measures difference was -3.6% (95% confidence interval: -4.6% to -2.6%; P < .0001). At week 16, more beinaglutide-treated patients achieved a weight reduction of 5% or more (58.2% vs. 25.4% [placebo], odds ratio: 4.4; P < .0001) and of 10% or more (21.3% vs. 5.1% [placebo], odds ratio: 5.5; P < .0001). Beinaglutide also resulted in greater waist circumference reduction (difference: -1.81 cm; P < .01). The weight regain rate 12 weeks after beinaglutide treatment was 0.78%. Nausea (transient and mild-to-moderate) was the most common adverse event in the beinaglutide group (49.3% vs. 7.1% [placebo]). More patients receiving beinaglutide discontinued treatment because of adverse events (5.9% vs. 0.7% [placebo]). Pancreatitis or an increased resting heart rate was not observed in the beinaglutide group.Beinaglutide combined with lifestyle intervention resulted in significant and clinically meaningful weight reduction with good tolerance in non-diabetic Chinese individuals with overweight or obesity.© 2023 The Authors. Diabetes, Obesity and Metabolism published by John Wiley & Sons Ltd.