This review shows that adding tirzepatide, a newer GLP‑1/GIP drug, after weight‑loss surgery can boost weight loss and improve blood sugar, blood pressure, and cholesterol, with mostly mild stomach side effects. It worked better than older drugs like semaglutide and liraglutide, especially for people who didn’t lose enough weight or regained weight after surgery.

Glucagon-Like- Peptide-1 (GLP-1) receptor agonist has an emerging role in obesity management. This meta-analysis and systematic review evaluated the effectiveness of GLP-1 receptor agonists in aiding weight loss and enhancing cardiometabolic health in patients with insufficient weight loss (IWL) or weight regain (WR) after bariatric surgery.  A comprehensive literature search (PubMed, Medline, Embase, Cochrane) was conducted following PRISMA guidelines. Included studies involved adults (≥18 years) treated with GLP-1 agonists either before or after bariatric surgery. Primary outcomes assessed were weight and BMI changes; secondary outcomes included metabolic improvements and adverse effects. 19 studies were included in the systematic review and meta-analysis. All included study involves at least one type of GLP-1 agonist for IWL or WR after bariatric surgery with duration of intervention between 3 months to 24 months. All studies showed significant weight and BMI changes from baseline after initiation of different types of GLP-1 agonist, with effects proportionate to length of intervention. Semaglutide outperformed liraglutide in achieving ≥10% and ≥15% weight loss post-surgery. Tirzepatide, a newer GLP-1/GIP agonist, showed even greater weight loss compared to semaglutide over 6 months. A systematic review of 6 studies on the metabolic effects of GLP-1 receptor agonists (RA) post-bariatric surgery highlighted significant improvements in glycemic control, blood pressure, cholesterol levels, and liver function. Adverse effects were mostly mild gastrointestinal symptoms with no severe events reported. GLP-1 agonists have emerged as a promising alternative to revisional surgery for patients experiencing insufficient weight loss (IWL) or weight regain (WR) after bariatric surgery. Tirzepatide, the newest GLP-1 /GIP agonist, has shown superior results compared to liraglutide and semaglutide. However, more long-term randomized controlled trials are needed to confirm these findings and further assess its effectiveness. Despite this, GLP-1 agonists consistently demonstrate significant weight loss and cardiometabolic improvements when compared to placebo or lifestyle modifications, making them a valuable treatment option for post-bariatric surgery patients. The online version contains supplementary material available at 10.1007/s00423-025-03831-4.