Comparison of Myo-Inositol and Metformin in the Management of Polycystic Ovary Syndrome (PCOS): A Systematic Review

Background: Polycystic ovary syndrome (PCOS) is a common endocrine disorder strongly driven by insulin resistance. Metformin is the traditional first-line pharmacological therapy; however, its long-term use is frequently challenging due to severe gastrointestinal side effects like nausea and diarrhea, which lead to poor treatment adherence. Given these limitations, myo-inositol has recently gained recognition as a promising, better-tolerated insulin-sensitizing alternative that restores insulin sensitivity without causing digestive disturbances.Methods: A systematic literature search for this review was conducted using PubMed, Cochrane CENTRAL and Google Scholar to compare the clinical efficacy, metabolic benefits and safety profile of myo-inositol versus metformin in women with PCOS. The evaluated primary outcomes included core metabolic parameters and medication tolerability. Secondary outcomes included endocrine profile changes, lipid panel improvements and fertility-related metrics.Results: The synthesized evidence based on 8 selected studies demonstrates that myo-inositol and metformin are comparably effective in improving core metabolic markers, reducing body mass index, and lowering insulin resistance. However, myo-inositol exhibits a markedly superior safety profile with a significantly lower incidence of gastrointestinal disturbances. Furthermore, myo-inositol provides greater clinical benefits in reducing hyperandrogenism, lowering testosterone and DHEA levels, reducing triglycerides, and optimizing outcomes during assisted reproductive procedures.Conclusion: Myo-inositol is a safe, effective and patient-friendly alternative to metformin. Providing comparable metabolic improvements with superior gastrointestinal tolerability and better androgen control, it serves as an optimal first-line therapy for PCOS management.