Impact of inositol supplementation on metabolic, endocrine, and anthropometric outcomes in women with polycystic ovarian syndrome: a comprehensive umbrella review

Inositols (IS), including myo-inositol (MI) and D-chiro-inositol (DCI), are increasingly being studied as potential treatments for polycystic ovarian syndrome (PCOS). However, the evidence is contradictory. This umbrella review aimed to examine the impacts of IS on women with PCOS. We searched PubMed, the Cochrane Library, Scopus, and Web of Science for relevant studies up to June 2026. Meta-analyses of RCTs involving women with PCOS treated with inositol (MI or DCI) versus placebo were included. Outcomes included metabolic, endocrine, or anthropometric factors. Studies using metformin as the control were excluded. A random-effects model was used to estimate pooled odds ratios (ORs) and mean differences (MDs), along with their 95% confidence intervals (CIs). The analysis included 18 meta-analyses involving 17,614 participants. Compared with placebo, IS supplementation improved ovulation rate (OR: 3.00) and was associated with a modest increase in clinical pregnancy rate (OR: 1.23). IS was associated with a lower levels of total testosterone (MD: − 13.70), free testosterone (MD: − 0.44), follicle-stimulating hormone (MD: − 0.82), androstenedione (MD: − 1.22), prolactin (MD: − 1.58), dehydroepiandrosterone sulfate (MD: − 82.89), fasting blood sugar (MD: − 0.95), fasting insulin (MD: − 2.93), insulin resistance (MD: − 1.01), and triglycerides (MD: − 24.04), and higher estradiol (MD: 2.35) and sex hormone-binding globulin levels (MD: 14.35). Higher doses of MI were associated with a significant reduction in body mass index (MD: − 0.40). Combination therapy with MI plus DCI resulted in a small decrease in waist-to-hip ratio (MD: − 0.02). There was significant heterogeneity for the majority of the outcomes. IS supplementation may be associated with a modest increase in ovulation and pregnancy rates, as well as favorable metabolic and endocrine profiles, in women with PCOS.