Semaglutide is found to be efficient for weight loss in patients with overweight or obesity with diabetes mellitus (DM). With a wide range of adverse events reported, the efficacy and safety of once-weekly subcutaneous semaglutide in individuals without DM, with overweight or obesity, is unclear. We conducted a comprehensive meta-analysis of randomized studies on once-weekly semaglutide in this patient population. We identified nine studies with 11,641 patients in the semaglutide group and 10,479 in the placebo group. We observed that semaglutide resulted in significant benefits, including change in body weight (%): mean difference (MD) of -11.49% (p < 0.0001), change in absolute body weight: MD of -11.74 kg (p < 0.0001), and change in waist circumference: MD of -9.06 cm (p < 0.0001). Gastrointestinal side effects are predominant including nausea: odds ratio (OR) of 4.06 (p < 0.0001), vomiting: OR of 4.43 (p < 0.0001), diarrhea: OR of 2.10 (p < 0.0001), constipation: OR of 2.43 (p < 0.0001), gallbladder disorders: OR of 1.26 (p = 0.010), and cholelithiasis: OR of 2.06 (p = 0.04). Serious adverse events were not statistically significant: OR of 1.06 (p = 0.82). However, the percentage of participants discontinuing due to adverse events and gastrointestinal side effects was statistically significant: ORs of 2.22 (p < 0.0001) and 3.77 (p < 0.0001), respectively. This study shows that in patients with overweight or obesity without DM, once-weekly subcutaneous semaglutide can significantly decrease body weight without risk of serious adverse events when compared with a placebo. However, gastrointestinal side effects are predominant with semaglutide, which can result in medication discontinuation.
