Real-World Outcomes of Tirzepatide and Semaglutide in 40,000+ Patients
Sustained Real-World Weight Loss in 40,000+ Patients
Substantial weight loss was achieved with GLP-1–based pharmacotherapy within a comprehensive digital obesity care model. Outcomes were maintained up to 24 months, with 57% of patients still in treatment, demonstrating strong long-term effectiveness in real-world care.
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Real-World Outcomes and Comparative Effectiveness of Tirzepatide, Semaglutide, and GLP-1 Therapy Switching in 40,712 People With Obesity in a Pan-European Single-Provider Digital Care Model (PO4.202)
Oliver Willacy1, Felix Wittström1, Oleg Ivanytskyi1, Elin Skoglund1, David Buchebner1, Kristofer Ringner1, Anna Sommerfeld1, Martin Carlsson1,2
1. Yazen Health AB, Malmö, Sweden
2. Department of Medicine and Optometry, eHealth Institute, Linnaeus University, Kalmar, Sweden
INTRODUCTION
Tirzepatide (TZP) and semaglutide (SEMA) are approved for the treatment of obesity, with randomised trials demonstrating up to 22% and 18% weight loss at maximal doses, respectively. However, large-scale real-world studies evaluating these agents within comprehensive care models combining pharmacotherapy with lifestyle intervention are limited. Yazen Health is a licensed Swedish healthcare provider offering a multidisciplinary digital care model for people with obesity in Sweden, Denmark, Norway, Germany, UK, Spain and The Netherlands.
METHODS
In this retrospective cohort study, we followed individuals with obesity (BMI ≥30 kg/m²) or overweight (BMI ≥27 kg/m² with comorbidities) who initiated treatment between January 2024 and January 2026.
and mean BMI was 33,2 kg/m² (SD 4.9)
Participants were categorised into three cohorts based on medication exposure: TZP, subcutaneous SEMA, or a mixed GLP-1 cohort. Weekly dose for TZP and SEMA was extracted from prescription information. Individuals who switched between TZP and SEMA or initiated other GLP-1–based therapies were classified into the mixed GLP-1 cohort from the month of change onward. Outcomes were analysed monthly until cohort size declined below 100 individuals. Retention was defined as the proportion of participants remaining in treatment after n months. Outcomes were assessed on treatment without imputation after discontinuation laboratory outcomes were compared between baseline and 7 months. Continuous variables were reported as mean (SD). Group differences were assessed using ANOVA with Tukey’s HSD. Analyses were unadjusted.
RESULTS
Among 40,712 individuals initiating treatment, approximately 30% were included in the TZP cohort, 26% in the SEMA cohort, and 44% in the mixed GLP-1 cohort. Retention was 69.1% at 12 months and 56.9% at 24 months.
At 12 months, mean doses of both drugs were below 50% of the maximum recommended dose, and mean percent body weight reduction was greater with TZP (−19.2%, SD 7.3) compared with SEMA (−16.0%, SD 7.2; p<0.001). Weight loss in the mixed GLP-1 cohort was −16.4% (SD 7.1), significantly lower than TZP (p<0.001) but not different from SEMA (p=0.24). Mean waist circumference reduction at 12 months was 16.3 cm (SD 9.2) with TZP, 14.4 cm (SD 9.0) with SEMA, and 14.8 cm (SD 9.3) in the mixed cohort. At 24 months, available data from the mixed GLP-1 cohort showed a mean weight loss of 18.7% (SD 7.7) and waist circumference reduction of 17.7 cm (SD 9.9). At 7 months, mean HbA1c decreased by −3.53 mmol/mol (SD 2.95), −3.10 mmol/mol (SD 2.86), and −3.15 mmol/mol (SD 2.99) in the TZP, SEMA, and mixed GLP-1 cohorts, respectively. Mean triglycerides decreased by −0.40 mmol/L (SD 0.66), −0.35 mmol/L (SD 0.82), and −0.34 mmol/L (SD 1.34).
More than half remained on treatment at 24 months.
CONCLUSION
In this large retrospective cohort study, we demonstrate substantial and sustained weight loss with different GLP-1 agents, with less than half of the maximum doses used in clinical trials. Weight loss was maintained up to 24 months, and more than half of participants were at that time still on treatment. To our knowledge, this represents one of the largest retrospective studies evaluating GLP-1–based pharmacotherapy within a comprehensive digital obesity care model.
Conflict of Interest: Martin Carlsson is a co-founder and employee of Yazen Health. All other authors are employees of Yazen Health.
Funding: There were no external funding sources for the current study.
References:
- Xie et al. 2026. Glucagon-Like Peptide-1 Receptor Agonist Switching and Treatment Persistence in Adults Without Diabetes. JAMA Netw Open. 9(3):e261272
- Gleason et al. 2024. Real-world persistence and adherence to glucagon-like peptide-1 receptor agonists among obese commercially insured adults without diabetes. J Manag Care Spec Pharm. 30(8):860–867
- Rodriguez et al. 2024. Semaglutide vs Tirzepatide for Weight Loss in Adults With Overweight or Obesity. JAMA Intern Med. 184(9):1056–1064. doi:10.1001/jamainternmed.2024.2525
May 11, 2026
May 12, 2026
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