Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have been used to reduce glucose levels in patients with type 2 diabetes mellitus since 2005. This meta-analysis discusses the mechanisms and potential benefits of several GLP-1 RAs. In particular, this meta-analysis focuses on the safety and associations with weight loss, glucose reduction, cardiovascular outcomes, heart failure, and renal outcomes of GLP-1 RAs to determine their benefits for patients with different conditions. In terms of glycemic control and weight loss, semaglutide was statistically superior to other GLP-1 RAs. In terms of cardiovascular outcomes, 14 mg of semaglutide taken orally once daily and 1.8 mg of liraglutide injected once daily reduced the incidence of cardiovascular death, whereas other GLP-1 RAs did not provide similar benefits. Moreover, semaglutide was associated with superior outcomes for heart failure and cardiovascular death in non-diabetic obesity patients, whereas liraglutide worsened heart failure outcomes in diabetic patients with a reduced ejection fraction. Additionally, semaglutide, dulaglutide, and liraglutide were beneficial in terms of composite renal outcomes: These GLP-1 RAs were significantly associated with less new or persistent macroalbuminuria, but not with improved eGFR deterioration or reduced requirement for renal replacement therapy. However, GLP-1 RAs may benefit patients with type 2 diabetes mellitus or obesity.