A newly published study from researchers at Lilly found greater weight loss with tirzepatide than semaglutide among adults treated for obesity in routine clinical practice.
Published in the Journal of Endocrinological Investigation, the analysis examined outcomes among adults with obesity without diabetes receiving treatment in routine care. At six months, patients receiving tirzepatide experienced greater average weight loss than those receiving semaglutide (−11.15% vs −8.83%). More patients also achieved clinically meaningful weight-loss thresholds, and greater improvement was observed in several cardiometabolic measures.
These results align with findings from the SURMOUNT-5 trial and earlier real-world evidence of the same therapies.
Real-world effectiveness of obesity therapies
In the study, researchers used Truveta Data to analyze 2,396 adults with obesity and without diabetes. The study used de-identified electronic health record (EHR) data from Truveta to compare weight-loss outcomes and changes in cardiometabolic changes over six months.
The primary outcome was percentage change in body weight. The researchers also examined how many patients reached weight-loss milestones of at least 5%, 10%, 15%, and 20%, as well as changes in body mass index, blood pressure, haemoglobin A1c, and other cardiometabolic measures.
Across these measures, tirzepatide was associated with greater weight loss, higher rates of clinically meaningful weight reduction, and greater improvement in body mass index, systolic and diastolic blood pressure, and haemoglobin A1c.
Evidence builds across trials and real-world studies
The Lilly study adds new real-world evidence to a pattern that has now been observed in both clinical trial and routine care settings.
In SURMOUNT-5, adults with obesity and without diabetes treated with tirzepatide achieved greater weight loss than those treated with semaglutide over 72 weeks. Lilly’s new study shows the same directional pattern much earlier in treatment, with greater average weight loss already visible at six months in routine clinical practice.
Earlier real-world evidence had already observed a similar pattern, more than a year before the SURMOUNT-5 results were reported. Taken together, the results point in the same direction across multiple study designs and patient populations. Randomized trials provide controlled validation, while real-world analyses help evaluate how therapies perform across broader and more diverse clinical settings.
