BACKGROUND: Suboptimal initial clinical response (SICR) and weight gain recurrence (WGR) are challenging issues following bariatric surgery. Recently, the promising weight loss effects of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have been applied to bariatric patients. We aimed to conduct a systematic review and meta-analysis to evaluate the efficacy and safety of GLP-1 RAs in the treatment of SICR and WGR after bariatric surgery. METHODS: A literature search was performed across online databases. The primary outcomes were percentage of total weight loss (%TWL) and absolute weight loss. Secondary outcomes included changes in biochemical markers and adverse effects (AEs). RESULTS: Nineteen studies including 1290 patients were included. After at least 3 months of treatment, the pooled %TWL was 9.24% for liraglutide, 11.38% for semaglutide, and 15.50% for tirzepatide, with corresponding weight reductions of 8.56 kg, 11.62 kg, and 12.60 kg, respectively. Additionally, %TWL and weight loss with liraglutide use were 7.65% and 7.47 kg for ≤ 6 months, 10.22% and 9.30 kg for 6-12 months, and 10.80% and 9.72 kg for ≥ 12 months. For semaglutide, the %TWL and weight reduction were 10.18% and 9.43 kg at 6 months, and 13.15% and 14.68 kg at 12 months. Biochemical markers including triglycerides, total cholesterol, low-density lipoprotein cholesterol, glycated hemoglobin, and alanine aminotransferase levels showed significant reductions after GLP-1 RA treatment. Common AEs were nausea (23%), vomiting (6%), diarrhea (6%), constipation (10%), headache (6%), fatigue (8%), abdominal pain (2%), and abdominal bloating (2%). The proportion of patients who discontinued the treatment due to AEs was 3%. CONCLUSIONS: GLP-1 RAs are effective and safe for treating SICR and WGR after bariatric surgery.