Semaglutide and Tirzepatide in a Remote Weight Management Program: 12-Month Retrospective Observational Study.

BACKGROUND: Obesity affects >890 million adults worldwide, and traditional lifestyle interventions often lack long-term success. While glucagonlike peptide-1 receptor agonists (GLP-1RAs) have shown strong weight loss outcomes, access to specialist care is limited by cost and capacity. OBJECTIVE: This study evaluated the effectiveness, feasibility, acceptability, and potential cost-effectiveness of a 12-month remote GLP-1RA-supported weight management program, comparing outcomes between tirzepatide and semaglutide. METHODS: This retrospective analysis included 339 participants (n=278, 82% women) who completed a 12-month remote weight management program using either tirzepatide (n=209, 61.7%) or semaglutide (n=130, 38.3%) between February and June 2024. The program combined medication, app-based behavioral support, coaching from registered dietitians and nutritionists, and clinical oversight. It featured 5 phases with evidence-based behavior change techniques, monthly monitoring, and safety protocols. Primary outcomes were mean weight change and proportions achieving ≥10% and ≥15% weight loss. Secondary outcomes included behavior changes, side effects, acceptability, feasibility, and estimated cost-effectiveness compared to National Health Service care. RESULTS: Mean weight change at 12 months was -22.9 kg (-22.1% of baseline weight, SD 8%; P<.001) in the tirzepatide cohort and -18.1 kg (-17.1% of baseline weight, SD 8.1%; P<.001) in the semaglutide cohort. Achievement of ≥10% weight loss occurred in 95.2% (199/209) of participants using tirzepatide and 83.1% (108/130) of participants using semaglutide, whereas ≥15% weight loss was achieved by 83.7% (175/209) and 56.2% (73/130) of the participants, respectively. The proportion of inactive participants (no weekly exercise) decreased substantially in both cohorts (tirzepatide: 31/209, 14.8% to 14/209, 6.7%; semaglutide: 29/130, 22.3% to 7/130, 5.4%; P<.001). Side effects decreased significantly over the 12-month period, with participants who reported no side effects increasing from 41.6% (87/209) to 60.3% (126/209; P<.001) in the tirzepatide cohort and from 53.8% (70/130) to 67.7% (88/130) in the semaglutide cohort (P=.02), whereas common initial side effects, including constipation, nausea, and fatigue, showed significant reductions (P<.001). Economic modeling suggested a 60% to 70% cost saving compared to specialist weight management services and a 10% to 60% cost saving compared to primary care in the National Health Service. CONCLUSIONS: This real-world evaluation demonstrates that remotely delivered, GLP-1RA-supported weight management programs can achieve weight loss outcomes that align closely with clinical trial results while potentially reducing health care costs by 10% to 70% compared to traditional UK services. Both the tirzepatide and semaglutide cohorts exceeded clinically significant weight loss thresholds with acceptable safety profiles and positive behavior changes. These findings support the feasibility and effectiveness of digital delivery models for expanding access to specialist obesity treatment within resource-constrained health care systems, with outcomes that compare favorably to pharmacological intervention alone.