Obesity is a common, chronic condition that represents a significant public health concern in the USA and worldwide, with a prevalence that has risen dramatically in the USA over the past few decades, affecting an estimated 41.9% of the adult population from 2017 to 2020 [1]. Obesity is a major risk factor for several medical conditions, such as type 2 diabetes mellitus (T2DM), hypertension, heart disease, stroke, gallbladder disease, osteoarthritis, and some cancers, and the presence of obesity-related comorbidities leads to substantially increased health care costs and greater mortality risk [2,3,4]. Several obesity management options are available, including caloric restriction, behavioral modification, bariatric surgery, and medication. The US Food and Drug Administration (FDA) has approved six drugs for long-term, chronic weight management [5].

Semaglutide injection 2.4 mg (Wegovy®; hereafter referred to as semaglutide 2.4 mg) is a once-weekly injectable glucagon-like peptide 1 (GLP-1) receptor agonist approved by the FDA in June 2021 for chronic weight management in adults with obesity or overweight with ≥ 1 weight-related comorbidity [6, 7]. The STEP series of phase 3, randomized, placebo-controlled clinical trials demonstrated the efficacy and safety of semaglutide 2.4 mg. Among 1961 patients without T2DM in the STEP 1 trial, the mean reduction in body weight from baseline was − 14.9% and − 2.4% at 68 weeks of follow-up in patients treated with semaglutide 2.4 mg and placebo, respectively (P < 0.001) [8]. The STEP 3 trial, which included semaglutide 2.4 mg as an adjunct to intensive behavior therapy and a low-calorie diet, further confirmed these findings in patients without T2DM, with patients experiencing a mean body weight reduction of − 16.0% with semaglutide 2.4 mg compared with − 5.7% with placebo at 68 weeks of follow-up [9]. In the STEP 2 trial, which included patients with T2DM, semaglutide 2.4 mg resulted in a mean weight reduction of − 9.6% compared with − 3.4% with placebo at 68 weeks of follow-up [10]. Moreover, the STEP 4 and 5 trials demonstrated that continued treatment with semaglutide 2.4 mg led to maintained weight loss over 68-week and 104-week follow-up periods, with mean weight reductions of − 17.4% and − 15.2%, respectively, compared with − 5.0% and − 2.6% with placebo, underscoring its important role for long-term weight management [11, 12]. Overall, the STEP trials demonstrated that semaglutide 2.4 mg is generally well tolerated, with the most common adverse events being mild to moderate gastrointestinal issues, thereby supporting its safety profile for chronic weight management [8,9,10,11,12]. Further, a review of prior network meta-analyses evaluating the effectiveness of GLP-1 receptor agonists for weight loss found that, across all time points evaluated, semaglutide 2.4 mg was associated with the greatest weight loss (− 11.5 to − 12.5 kg compared with placebo) [13].

Real-world evidence on the long-term effectiveness of semaglutide 2.4 mg is currently limited owing to the relatively recent approval of this therapy; however, several real-world studies have found substantial weight loss results for patients. In a retrospective cohort study that reviewed electronic medical records, among patients with overweight or obesity who were treated with semaglutide 2.4 mg, the mean (standard deviation [SD]) percent weight loss from baseline was − 10.9% (5.8%) at 6 months [14]. Other retrospective cohort studies in patients with overweight or obesity who were treated with semaglutide 2.4 mg described mean (SD) percent weight loss of − 10.0% (6.6%) at 6 months of follow-up and − 13.4% (8.0%) and − 14.5% (SD not reported) at 1 year of follow-up [15,16,17].

In tandem with treatment, digital patient support programs can play a positive role in the management of patients with overweight and obesity, with several potential benefits, especially given the need for easily accessible information [18,19,20]. For instance, among patients in the UK who were treated with semaglutide (semaglutide indicated for T2DM [Ozempic®] or semaglutide 2.4 mg) or tirzepatide (a glucose-dependent insulinotropic polypeptide and GLP-1 receptor co-agonist indicated for T2DM and overweight/obesity), active engagement with digital health platforms for weight loss—defined by the inclusion of coaching sessions, digital application use, and regular weight tracking tools—led to a mean weight loss of − 11.5% (95% CI − 11.5% to − 11.6%) at 5 months of follow-up versus − 8.0% (95% CI − 7.9% to − 8.0%) among patients who did not use these platforms (P < 0.001) [21].

Given the demonstrated clinical efficacy and safety of semaglutide 2.4 mg and the limited data on its real-world long-term effectiveness, our study aimed to evaluate the characteristics and real-world outcomes of patients with overweight or obesity who were treated with semaglutide 2.4 mg using patient-reported data from the WeGoTogether digital patient support program over a follow-up period of up to 24 months.