SURMOUNT-5

In SURMOUNT-5, a phase 3b trial of tirzepatide in adults with obesity but without type 2 diabetes (n=751), mean body weight fell 20.2% on tirzepatide, maximum tolerated dose over 72 weeks, against 13.7% on semaglutide, maximum tolerated dose (Aronne LJ et al. N Engl J Med 2025 (SURMOUNT-5)).

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Updated 24 September 2026

Tirzepatide Explained: SURMOUNT, SURPASS and Philippines Status1:58Transcript and chapters

Results

Mean percent change in body weight by arm, as each source reports it. Navy bars are the trial arms, grey bars the comparator. Bars from different trials are not a head-to-head comparison: populations, durations and estimands differ.

Side effects reported

SURMOUNT-5: The abstract does not name the estimand or give adverse event rates.

Design

Trial design and sources

Compound: Tirzepatide
Phase: 3b
Population: Adults with obesity but without type 2 diabetes
Participants randomised: 751
Duration: 72 weeks
Primary endpoint: Percent change in weight from baseline to week 72
Estimand: Not stated in the source read
Read out: 11 May 2025

Head-to-head, open-label: tirzepatide (10 or 15 mg) against semaglutide (1.7 or 2.4 mg). The abstract does not name the estimand or give adverse event rates.

Aronne LJ et al. N Engl J Med 2025 (SURMOUNT-5) open · checked 23 September 2026
ClinicalTrials.gov NCT05822830 open · checked 23 September 2026
Registry: NCT05822830

Questions

SURMOUNT-5, answered

What did SURMOUNT-5 find?

What side effects were reported in SURMOUNT-5?