STEP 12 Trial Finds Semaglutide Cut Bodyweight by Nearly 10 Percentage Points More Than Placebo in Chinese Adults

The Lancet Diabetes & Endocrinology published the results of STEP 12 on August 10, 2026, a phase 3b randomized trial testing once-weekly semaglutide 2.4 mg in adults with overweight or obesity in mainland China and Taiwan. The trial is notable for using BMI thresholds defined for local populations rather than the higher BMI cutoffs used in earlier STEP trials conducted primarily in the United States and Europe. The study was funded by Novo Nordisk, which manufactures semaglutide and markets it as Wegovy for chronic weight management.

The trial enrolled adults with a BMI of 24 to under 28 kg/m2 and at least one weight-related comorbidity, or a BMI of 28 to under 30 kg/m2, with or without type 2 diabetes, at 19 sites across mainland China and Taiwan. Of 254 people screened between September 15, 2023 and May 7, 2025, 242 were randomized 2:1 to once-weekly subcutaneous semaglutide 2.4 mg or placebo, both combined with lifestyle intervention, for 44 weeks. Randomization was stratified and performed by the study sponsor. Half the participants (50.0%) were female, and 47 (19.4%) had type 2 diabetes.

At week 44, the coprimary endpoints both favored semaglutide. Bodyweight fell by an average of 12.1% (SE 0.6) with semaglutide compared with 2.2% (SE 0.8) with placebo, an estimated treatment difference of 9.9 percentage points (95% CI 8.0-11.8; p<0.0001). A greater proportion of the semaglutide group achieved at least 5% bodyweight reduction: 80.5% versus 24.4% on placebo, an odds ratio of 14.8 (95% CI 7.4-29.6; p<0.0001). Missing data at week 44 were imputed using washout multiple imputation.

Adverse events were reported in 141 of 161 participants (87.6%) in the semaglutide group and 61 of 81 participants (75.3%) on placebo, with gastrointestinal disorders, including nausea, vomiting, and diarrhea, the most common category. The published findings describe the safety profile as consistent with semaglutide's established profile from prior trials in other populations. The trial is registered with ClinicalTrials.gov as NCT06041217 and is listed as completed.

Semaglutide is already approved by the FDA, the European Medicines Agency, and Australia's Therapeutic Goods Administration, marketed as Wegovy for chronic weight management and as Ozempic and Rybelsus for type 2 diabetes. STEP 12 does not change that regulatory status in any market. Several of the trial's authors are employees or shareholders of Novo Nordisk. The results describe outcomes observed in the trial population and are not treatment or dosing guidance; weight management decisions should be made with a qualified clinician.