Abstract Disclosure: F.A. Kelly: None. A.D. Lôbo: None. I.B. Andrade: None. P.G. Lima: None. I.P. da Silva: None. M.C. Souza: None. V. Morbach: None. M.S. Barros: None. F.A. Moraes: None. M.B. Jardine: None. L.M. Lopes: None. M.P. Lima: None. M.G. Leite: None. R.Y. Ura Sudo: None. J.C. Cardoso: None. A.M. De Almeida: None. F.D. Pessôa: None. Metformin was the first medication targeting insulin resistance in PCOS, and it has been extensively studied as a metabolic treatment option. It addresses the chronic inflammatory state of PCOS and improves ovulation, metabolic parameters, and fertility.In recent years, inositols, specifically myo-inositol, and D-chiro-inositol, have emerged as potential treatment options for PCOS. These compounds act as a messenger for hormones, including insulin and follicle-stimulating hormones. Inositols effectively address insulin resistance and modulate the insulin signaling pathways.Although inositols have recently been included in the recommendations of the European Journal of Endocrinology's 2023 International evidence-based guideline for improvement in metabolic measures and considered with benefits in ovulation, hirsutism, and weight in patients with PCOS, the confidence in the available evidence supporting their use is considered to be limited. We aimed to perform a meta-analysis to understand the role of inositol, on glycemic control, LH/FSH ratio, hirsutism, HOMA-IR, and body mass index (BMI) in individuals with polycystic ovary syndrome (PCOS).PubMed, Embase, and Cochrane databases were systematically searched for RCTs comparing the use of metformin alone versus metformin and inositol in patients with polycystic ovary syndrome. Statistical analysis was performed in R software 4.3.1. A random-effects model was used to calculate the risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals (CIs). A p-value of < 0.05 was considered statistically significant. Heterogeneity was examined with the Cochran Q test, prediction interval, and I² statistics. A total of 4 RCTs and 277 patients were included, of whom 138 were randomized to metformin alone and 139 to metformin plus myo-inositol. Compared with metformin alone, Myo-inositol plus Metformin significantly reduced hirsutism (MD -0.97; 95% CI -1.53; -0.40; p=0.0008) and LH/FSH ratio (MD -0.15; 95% CI -0.26, -0.03; p=0.02). There was no significant difference between groups for BMI (MD: 0.97; 95% CI -0.37, 2.32; p=0.16) and HOMA-IR (MD -0.17; 95% CI -0.35, 0.01; p=0.07).In this meta-analysis of RCTs of patients with polycystic ovary syndrome, inositol was associated with a reduction in hirsutism and LH/FSH ratio, compared with metformin monotherapy. Further studies are needed to clarify whether there are benefits for the use of inositol in PCOS treatment. Presentation: 6/3/2024