Plain Language Summary
Real-world service evaluation of Voyager—a digital weight management program combining tirzepatide with nutritional and behavioral support in a UK digital weight loss service—assessing 12-month holistic outcomes including weight, mental health, and wellbeing. Evaluates whether the digital integrated approach improves outcomes beyond pharmacotherapy alone. Provides evidence for tirzepatide within a digital-first integrated care model—demonstrating real-world effectiveness when GLP-1/GIP agonist pharmacotherapy is embedded in structured behavioral and nutritional support delivered through digital health infrastructure.
Abstract
Introduction Recent pharmacological advancements, such as tirzepatide, a dual GIP/GLP-1 receptor agonist, offer new therapeutic options, delivering substantial weight loss with potential mental health and well-being benefits. Digital weight loss services (DWLS) that combine anti-obesity medication with nutritional and behavioural support are increasingly used, but real-world evidence remains limited as clinical trial outcomes may not reflect routine practice. This service evaluation assessed 12-month outcomes of individuals enrolled in Voyager, a pilot programme delivered by the Voy DWLS. Methods UK residents (n=60) aged 18-65 with body mass index (BMI) ≥30 kg/m², naive to prior anti-obesity medication. Participants attended the Voyager programme between July 2024 and August 2025, comprising tirzepatide treatment and digital interventions (health coaching, side effects tracking, clinical support, app access, and webinars). The primary outcome was the percentage total body weight loss (WL) from baseline to 12 months. Secondary outcomes included anthropometric measures, patient-reported outcomes (Binge Eating Scale (BES) and Patient Health Questionnaire-9 (PHQ-9) scores), blood pressure, side effects, and laboratory results. Statistical analyses employed descriptive statistics, paired t-tests, and linear mixed-effects models. Results Participants were predominantly female (90%, n=54), with a mean age of 44.6±11.1 years and baseline BMI of 37.1±6.2 kg/m². At 12 months, mean WL reached 22.7% (95% CI 20.92-24.48; p<0.001). Waist and hip circumference, and waist-to-hip ratio, declined significantly. BES scores fell by 18 points (95% CI 14.5-21.67) and PHQ-9 by 3.06 points (95% CI 2.26-3.87). Mean systolic and diastolic blood pressure decreased by 9.07 mmHg (95% CI 5.52-12.61) and 4.90 mmHg (95% CI 2.53-7.26), respectively (all p<0.001). Nausea was the most common side effect and decreased over time. Significant longitudinal improvements occurred across cardiometabolic markers, including glycated haemoglobin (HbA1c), low-density lipoprotein (LDL) cholesterol, total cholesterol, and cholesterol/high-density lipoprotein (HDL) ratio; all five participants with prediabetes normalised HbA1c by 12 months. Conclusion The Voyager programme integrating tirzepatide achieved clinically meaningful weight loss and broad metabolic and psychological improvements over 12 months, supporting integrated pharmacological-digital approaches to obesity care.
Authors
Sikorska, Lena M; Liu, Vivian N; Johnson, Hans; Chaudry, Earim; Reisel, Daniel; Clift, Ashley K; Huang, David R