Clinical research

SURMOUNT-5: Tirzepatide versus semaglutide, head to head

Phase 3b, randomised, open-label, active-controlled head-to-head. 751 randomised 1:1, over 72 weeks. Sponsor: Eli Lilly and Company.

SURMOUNT-5 (NCT05822830) tested tirzepatide once weekly at maximum tolerated dose at 10 mg or 15 mg against semaglutide once weekly at maximum tolerated dose, 1.7 mg or 2.4 mg in adults with obesity but without type 2 diabetes; bmi 30 or above, or 27 or above with at least one obesity-related complication. 32 sites in the united states and puerto rico, april 2023 to november 2024.Least-squares mean weight change of −20.2% with tirzepatide versus −13.7% with semaglutide (P<0.001); −22.8 kg versus −15.0 kg; waist circumference −18.4 cm versus −13.0 cm Primary source linked: the source is a citable peer-reviewed / registry record, which we have not independently re-extracted from the full paper in this session.

Study design

Results

Least-squares mean weight change of −20.2% with tirzepatide versus −13.7% with semaglutide (P<0.001); −22.8 kg versus −15.0 kg; waist circumference −18.4 cm versus −13.0 cm

Adverse events & discontinuations

Most adverse events were gastrointestinal and mild to moderate. Serious adverse events occurred in 4.8% of the tirzepatide group and 3.5% of the semaglutide group

Six participants in each group discontinued because of adverse events

Limitations

Open-label, so neither participants nor investigators were blinded. Industry-funded. Compares maximum tolerated doses, not fixed doses, and more semaglutide participants reached their top dose than tirzepatide participants in some real-world analyses. Excludes people with type 2 diabetes.

Practical interpretation

This is one trial, reported by Eli Lilly and Company, read directly against the registry and publication linked below — GLP Ranked has not re-run the statistics or obtained the patient-level data. Results describe group averages under trial conditions and may not describe any individual's outcome, including with a compounded, non-FDA-approved version of a similar active ingredient. Always check the primary source before citing a specific number.