Weight-loss surgery beat tirzepatide in one diverse cohort

The study was a retrospective, single-center comparison in a diverse, urban patient population ¹. The primary outcomes were changes in body mass index, a measure of weight relative to height, excess weight loss, and total weight loss at 3, 6, and 12 months ¹. The analyses showed differences between the surgery and tirzepatide groups at every time point that were unlikely to be due to chance ¹. At 12 months, the sleeve gastrectomy group had lost 30% of total body weight and reduced body mass index by 12 kg/m2, while the tirzepatide group had lost 12% of total body weight and reduced body mass index by 7 kg/m2 ¹. That is a wide difference in this selected matched cohort.

The 12% total weight loss with tirzepatide in this surgery comparison is lower than some earlier reports. A network meta-analysis, a technique that combines results from many randomized trials and permits indirect comparisons between treatments, found that tirzepatide 15 mg produced a mean weight reduction of about 17.97 percentage points versus placebo ⁴. A large UK real-world cohort reported mean weight loss of 17.4% at 12 months ⁵. Those reports used different populations and designs than this single-center cohort. PubMed+2

The surgery result does not erase the evidence for tirzepatide as a medication option. Major guidelines place tirzepatide among first-line medication options for adults with obesity ⁶. Head-to-head evidence has shown that tirzepatide beats semaglutide by about 4.28 percentage points of weight loss ⁷. What the new study adds is a direct comparison with surgery in a population that has been underrepresented in many trials. PubMed

The systematic review pulled together 20 studies and 2 regulatory reviews on mood and mental health safety in adults with type 2 diabetes or obesity ². Randomized evidence, including two large 2025 meta-analyses and pooled analyses of semaglutide and tirzepatide, showed no increased risk of suicidal thoughts, depression, or anxiety ². Active-comparator studies from the United States, Scandinavia, and the United Kingdom also found no clear increase after accounting for background differences. DOI

The review highlighted a limit. Many randomized trials excluded people with certain psychiatric conditions, so the findings may not apply to those groups ². Some less controlled reports flagged possible concerns, but the review said those methods could not separate the drug from other explanations. DOI

A retrospective cohort study used a large US database to compare people prescribed tirzepatide or semaglutide before primary knee or hip replacement ³. After matching 2,858 people in each group, there were no clear differences in surgical, medical, or implant-related outcomes at 90 days or one year ³. At two years, the tirzepatide group had lower odds of mechanical complications, with an odds ratio of 0.64, meaning the odds were 36% lower ³. Mechanical complications are problems with the parts of the artificial joint. The odds of an infection around the artificial joint were also lower, with an odds ratio of 0.64, meaning the odds were 36% lower ³. Reoperation rates were similar ³. The authors describe these as preliminary associations that need further study. PubMed

The surgery comparison is retrospective and from a single center, so it cannot prove that sleeve gastrectomy would beat tirzepatide by the same margin in a randomized trial ¹. We also do not know how the two options compare beyond 12 months in this population ¹. The mood safety review is limited by the exclusion of some psychiatric histories from randomized trials ². The joint surgery findings came from a database study and need larger cohorts to improve precision ³. None of these reports establishes a long-term, causal answer.