Objectives: To analyze the existing literature on the outcomes of metformin usage among prediabetic patients. Methods: A thorough search across four databases identified 914 relevant publications. After removing duplicates using Rayyan QCRI and screening for relevance, 77 full-text articles were reviewed, with 6 studies ultimately meeting the criteria for inclusion. Results: We included six studies with a total of 295 pre-diabetic patients and 197 (66.8%) were females. Across the included studies, metformin demonstrated consistent benefits in improving insulin sensitivity and lowering fasting glucose and HbA1c levels, particularly when combined with lifestyle interventions such as exercise. Several studies showed delayed or reduced progression to type 2 diabetes (T2D). Metformin was especially effective in individuals with higher baseline fasting plasma glucose or insulin resistance. Adverse effects were minimal and infrequently reported. However, metformin alone was not universally effective in preventing diabetes, emphasizing the importance of combined interventions. Conclusion: Metformin is a safe and effective adjunct therapy for delaying or preventing T2D in individuals with prediabetes, particularly when used alongside lifestyle changes. Early initiation may offer greater benefits in preserving insulin function and reducing β-cell stress. Future research should explore long-term outcomes and optimal patient selection criteria.