Real-World Effectiveness and Treatment Patterns of Tirzepatide in a Large UK Digital Health Cohort.

BACKGROUND: Tirzepatide has demonstrated substantial weight-loss efficacy in clinical trials, but real-world evidence from routine digital prescribing remains limited. METHODS: We conducted a retrospective cohort study of adults initiating tirzepatide for obesity via a UK digital prescribing service between March 2024 and July 2025. Linked order-level prescribing data and self-reported weights were analysed to estimate percentage weight change at 3, 6, 9, and 12 months. Adherence was assessed using mean days between medication orders. A 6-month survey captured patient-reported outcomes including lifestyle changes and side effects. The primary endpoint was percentage weight change at 6 months. RESULTS: Following analysis of 630 545 eligible patients (80.3% female, mean BMI 36.1 kg/m2 [SD 5.8]), mean weight loss in those with recorded weights was -13.5% (95% CI: -13.56 to -13.51) at 6 months (n = 270 309) and -17.4% (95% CI: -17.5 to -17.3) at 12 months (n = 58 434). At 6 months, 89.9% achieved ≥ 5% weight loss and 72.1% achieved ≥ 10%. More regular ordering cadence was associated with greater weight loss, and clinically meaningful outcomes were frequently achieved without escalation beyond intermediate doses. Treatment persistence was higher among patients from less deprived areas, with 26.1% more prescription orders than those from the most deprived areas. Patients reported improvements in mobility (46.7%) and mood (45.9%), and reduced alcohol consumption (26.7%). CONCLUSIONS: Tirzepatide was associated with substantial weight loss and significant patient-reported benefits including mood and mobility improvement. Treatment continuity was a correlate of effectiveness, and maximal dose escalation was often unnecessary. These findings support the effective delivery of GLP-1 medication for the treatment of obesity via digital prescribing pathways.