ASMBS 2026
Bariatric surgery an effective add-on to GLP-1 therapy
Clinical takeaway: Bariatric surgery is a meaningful next step for patients on GLP-1 therapy, not a redundant one. Prior medication use does not compromise surgical outcomes and may be part of an effective sequenced approach to severe obesity.
GLP-1 drugs have expanded obesity treatment options, but medication alone often falls short of the weight loss many patients need. Whether surgery can reliably extend those gains is a question addressed in a recent study presented at the annual meeting of the American Society for Metabolic and Bariatric Surgery.
Pairing medication with surgery deepened that result. Patients who had used semaglutide or tirzepatide before their procedures lost about 8% of body weight on medication — then achieved total weight loss exceeding 25% after gastric bypass and roughly 20% after sleeve gastrectomy. Patients who went directly to surgery without prior drug exposure lost only about 2% to 3% more, indicating GLP-1s did little to blunt surgical efficacy.
Patients who used GLP-1s before surgery were also more likely to resume them afterward. At one year, 44% of gastric bypass patients and 57% of sleeve gastrectomy patients had restarted medication; by three years, that rose to about two-thirds across both groups — higher than rates seen among patients who'd gone directly to surgery.
The analysis compared more than 6,700 patients with prior GLP-1 use against nearly 127,000 who proceeded directly to surgery, drawing on Epic Cosmos electronic health records from 2019 to 2025. The findings have not yet been peer reviewed.
Together, the data support a sequenced model of care in which GLP-1 therapy and surgery work as complementary tools rather than competing ones.
"Medications may start the weight loss journey, but surgery remains the most effective and durable treatment for most patients with severe obesity," said Richard Peterson, MD, MPH, FASMBS, president of the ASMBS and professor of surgery at UT Health San Antonio, who was not involved in the study.
Source: Kozato A, Chhabra KR, et al. American Society for Metabolic and Bariatric Surgery Annual Meeting. May 5, 2026. Bariatric Surgery Effectiveness After GLP-1 Agonist Weight Loss