Patients who take GLP-1 weight-loss drugs and later have bariatric surgery still get the full benefit of the operation, according to research presented at the annual meeting of the American Society for Metabolic and Bariatric Surgery (ASMBS). The ASMBS announced the findings on May 5, 2026.
What the study found
Researchers from the NYU Grossman School of Medicine reviewed health records of more than 6,700 patients prescribed semaglutide or tirzepatide in the six months before surgery. They compared them with roughly 127,000 surgery patients who had not used GLP-1 drugs.
- Patients lost about 8% of their body weight on GLP-1 drugs before surgery.
- Total weight loss rose to more than 25% after gastric bypass and about 20% after sleeve gastrectomy.
- Patients who went straight to surgery lost only about 2% to 3% more after their operations, which shows prior GLP-1 use did little to reduce the surgery’s effect.
The study also found that many patients who used GLP-1 drugs before surgery went back on them afterward. By three years, about two-thirds were taking them again. Patients who had surgery without prior GLP-1 use were less likely to need the medication long term.
Why it matters for Tijuana
Bariatric surgery has long been one of Tijuana’s leading medical tourism specialties. The Baja Health Cluster has said demand dipped as more patients turn to weight-loss medications. The ASMBS findings suggest the two approaches can work together: medication can start the weight loss, and surgery remains the most effective and durable treatment for most people with severe obesity. Surgeons in Tijuana say patients are still having surgery even as GLP-1 drugs become more common.
Questions to ask before surgery
- Should I stop or adjust my GLP-1 medication before surgery, and when?
- Which procedure, bypass or sleeve, fits my health history?
- What nutrition and follow-up plan will I have after I return home?
Resumen en español
Un estudio presentado en la reunión anual de la ASMBS el 5 de mayo de 2026 encontró que los pacientes que usan medicamentos GLP-1 antes de la cirugía bariátrica logran una pérdida de peso total de más del 25% con bypass gástrico y cerca del 20% con manga gástrica. El uso previo de estos fármacos casi no reduce la eficacia de la cirugía. Para Tijuana, los resultados indican que medicamentos y cirugía pueden complementarse.
This article is for general information and is not medical advice. Talk with your doctor before starting or stopping any medication.
