Inositol Research Database
The clinical studies behind our guides — organised by dose, duration, population and outcome. Every entry links to its PubMed source, and each one was verified during our editorial review.
Evidence levels:SolidPromisingPreliminary
33 studyies
| Study | Type | Population | Dose / protocol | Duration | Key finding | Evidence | Source |
|---|---|---|---|---|---|---|---|
A 3.6:1 myo-inositol to D-chiro-inositol ratio and antioxidant-based food supplement before IVF improves fertility in women with PCOS: a pilot observational retrospective cohort study Belchín Fernández P, Calvente V, Gómez Roso MJ, et al. · 2026 · J Obstet Gynaecol | Retrospective cohort (pilot) | 92 women with PCOS (Rotterdam criteria) undergoing IVF-ICSI | MYO:DCI 3.6:1 + antioxidants ≥1 month before ovarian stimulation | ≥1 month pre-IVF | Pilot cohort: higher fertilization rate (77.7% vs 71.6%, P=0.03) and fewer cycles without a good-quality blastocyst in the supplemented group. Oocyte yield and MII rates were comparable. Observational design limits causal claims. | Promising | PMID 42334964 |
Effects of inositol in women with polycystic ovary syndrome: an umbrella review of meta-analyses from randomized controlled trials Duan M, Yang M, Li C, et al. · 2026 · Front Endocrinol (Lausanne) | Umbrella review of 13 meta-analyses | PCOS women; 13 meta-analyses, 85 evidence items | Inositol (MI, DCI, or combined) vs placebo/folic acid | — | Inositol improved LH, SHBG, androstenedione, HOMA-IR, fasting insulin, triglycerides, ovulation (RR 2.75) and live birth (RR 2.29) vs placebo/folic acid. But GRADE found no high-quality evidence (18.9% moderate, 41.1% very low) and DCI monotherapy should be used with caution; MI/MI+FA looked superior for metabolic and reproductive outcomes. | Promising | PMID 41757236 |
The effect of myo-inositol supplementation on gestational diabetes mellitus prevention: a systematic review and meta-analysis Poyatos-León R, Martínez-Vizcaíno V, Sequí-Domínguez I, Sanabria-Martínez G · 2026 · Am J Obstet Gynecol | SR & meta-analysis | 4,765 women without preexisting diabetes (12 RCTs) | Myo-inositol vs placebo or standard care, during pregnancy or preconception | Varied | Myo-inositol substantially reduced the risk of gestational diabetes across 12 RCTs (4,765 women). Most trials rated moderate to high quality with some bias concerns. | Solid | PMID 42242341 |
Metformin and Myo-Inositol: A Comparative Analysis Russo M, Oliva MM, Nordio M, et al. · 2026 · Gynecol Obstet Invest | Narrative review | Comparative review (PCOS focus) | — | — | Argues myo-inositol has a more acceptable safety profile than metformin (which carries GI side effects and rare lactic acidosis risk) and is a naturally occurring molecule. Authors note metformin's safety in pregnancy remains controversial. Interpret with caution: several authors are affiliated with inositol manufacturers/EGOI-PCOS. | Promising | PMID 41269915 |
Efficacy of inositol supplementation for the prevention and treatment of gestational diabetes in pregnant women: Results from an umbrella meta-analysis Lin L, Zhou L, Zhang X, et al. · 2026 · Int J Gynaecol Obstet | Umbrella meta-analysis | 19 studies, 17,932 participants | Inositol (myo or D-chiro) vs placebo | — | Inositol linked to lower GDM risk (RR 0.42), less insulin therapy, hypertension, preterm birth and neonatal hypoglycemia. Umbrella analyses pool heterogeneous prevention and management trials — and a large 2025 JAMA RCT found no benefit in PCOS pregnancy, so treat the direction as promising but contested. | Promising | PMID 41792927 |
Oral myo-inositol plus D-chiro-inositol (3.6:1) reduces insulin resistance pathway biomarkers in acne-involved skin among subjects with metabolic comorbidities: A gene expression study Vaccaro M, Emanuele E, Minoretti P, et al. · 2026 · Neuro Endocrinol Lett | Open-label, pre-post biopsy study | 45 adults with acne and PCOS or metabolic syndrome | MI/DCI 1,100 mg + 300 mg daily (3.6:1) | 12 weeks | Exploratory evidence: MI/DCI increased FOXO1 and reduced MTOR and IGF1 in acne-involved skin, with clinical improvement in 82.2% of participants. Uncontrolled single-arm design — useful mechanistic support for the acne/IR link, not proof of clinical efficacy. | Preliminary | PMID 42165798 |
Comparison of metformin with inositol versus metformin alone in women with polycystic ovary syndrome: a systematic review and meta-analysis of randomized controlled trials Kelly FA, et al. · 2025 · Endocrine | SR & meta-analysis | 388 women with PCOS (6 RCTs) | Metformin + inositol vs metformin alone | 3–6 months | Combination improved cycle regularity (RR 1.56) and hirsutism and LH/FSH; no significant difference in glucose or HOMA-IR. | Solid | PMID 39331347 |
Myo-inositol Supplementation to Prevent Pregnancy Complications in Polycystic Ovary Syndrome: A Randomized Clinical Trial van der Wel AWT, Frank CMC, Bout-Rebel R, et al. · 2025 · JAMA | RCT (double-blind) | 464 pregnant women with PCOS (13 Dutch hospitals) | Myo-inositol 2 g + folic acid 0.2 mg twice daily vs placebo (folic acid only) | 8–16 weeks' gestation until delivery | Negative result: myo-inositol did not reduce the composite of gestational diabetes, preeclampsia or preterm birth in PCOS pregnancy (25.0% vs 26.8%; RR 0.93, P=0.67). The largest rigorous RCT in this setting — important counterweight to the positive meta-analyses. | Solid | PMID 40920401 |
Efficacy of N-Acetylcysteine in Polycystic Ovary Syndrome: Systematic Review and Meta-Analysis Viña I, Viña JR, Carranza M, Mariscal G · 2025 · Nutrients | SR & meta-analysis | 2,515 women with PCOS (22 studies) | N-acetylcysteine vs placebo, metformin or clomiphene | Varied | NAC increased progesterone and endometrial thickness; no significant differences in estradiol, SHBG or FSH. Two authors are affiliated with a supplement company. | Promising | PMID 39861414 |
Inositol for Polycystic Ovary Syndrome: A Systematic Review and Meta-analysis to Inform the 2023 Update of the International Evidence-based PCOS Guidelines Fitz V, et al. · 2024 · J Clin Endocrinol Metab | SR & meta-analysis | Women with PCOS | 40:1-style myo-inositol/D-chiro protocols | Roughly 3–6 months (pooled) | Meta-analysis informing the 2023 international guideline; the evidence base is built on 40:1-style protocols. | Solid | PMID 38163998 |
Different supplements improve insulin resistance, hormonal functions, and oxidative stress on overweight and obese women with polycystic ovary syndrome: a systematic review and meta-analysis Ren X, et al. · 2024 · Front Endocrinol | SR & meta-analysis | Overweight and obese women with PCOS | Various supplements compared | — | Several supplements improved insulin resistance and hormonal markers in overweight/obese PCOS; effect sizes vary by supplement. | Solid | PMID 39722805 |
Inositol is an effective and safe treatment in polycystic ovary syndrome: a systematic review and meta-analysis of randomized controlled trials Greff D, et al. · 2023 | SR & meta-analysis | Women with PCOS (pooled RCTs) | Various inositol protocols | Varied | Inositol judged effective and safe; adverse events mostly mild gastrointestinal and typically dose-related. | Solid | PMID 36703143 |
Recommendations from the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome International PCOS Guideline Network · 2023 | Clinical guideline | Women with PCOS | Inositol among the options considered | — | The 2023 international guideline keeps inositol among the options worth considering in PCOS care. | Solid | Source ↗ |
Comparison of nutritional supplements in improving glycolipid metabolism and endocrine function in polycystic ovary syndrome: a systematic review and network meta-analysis Hu X, et al. · 2023 · PeerJ | SR & meta-analysis | Women with PCOS (network meta-analysis of supplements) | Nutritional supplements compared (incl. chromium, inositol, omega-3) | — | In the network meta-analysis, chromium improved insulin and HOMA-IR; supplement effects on metabolic markers vary by agent. | Solid | PMID 38025704 |
A randomized controlled trial comparing myoinositol with metformin versus metformin monotherapy in polycystic ovary syndrome Nazirudeen R, et al. · 2023 · Clin Endocrinol | RCT | 53 overweight/obese women with PCOS (18–35 y) | Myo-inositol + metformin vs metformin alone | 6 months | Better cycle regularity and quality-of-life scores with the combination; pregnancy rates equal between arms. | Promising | PMID 37265016 |
Folic Acid Supplementation to Prevent Neural Tube Defects: US Preventive Services Task Force Reaffirmation Recommendation Statement US Preventive Services Task Force · 2023 · JAMA | Recommendation statement | People planning or possibly becoming pregnant | Folic acid 400–800 mcg daily | — | USPSTF recommends 400–800 mcg of folic acid daily for anyone planning or possibly becoming pregnant (A recommendation). | Solid | PMID 37526713 |
The effect of magnesium alone or its combination with other supplements on the markers of inflammation, OS and metabolism in women with polycystic ovarian syndrome (PCOS): A systematic review Li R, et al. · 2022 · Front Endocrinol | SR & meta-analysis | Women with PCOS | Magnesium alone or combined with other supplements | Varied | Magnesium linked with improvements in metabolic and inflammatory markers in PCOS. | Promising | PMID 35992132 |
Effectiveness of inositol, metformin and their combination in women with PCOS undergoing assisted reproduction: systematic review and meta-analysis Unanyan A, et al. · 2022 · Gynecol Endocrinol | SR & meta-analysis | 4,668 women with PCOS undergoing assisted reproduction (35 RCTs) | Metformin, inositol, or combinations | — | No significant inositol vs control difference in clinical pregnancy; metformin improved clinical pregnancy in ART; combination arms too few to pool. | Promising | PMID 36285403 |
Inositol Treatment for PCOS Should Be Science-Based and Not Arbitrary Roseff S, Montenegro M · 2020 · Int J Endocrinol | Review / commentary | Women with PCOS | Inositol ratios | — | Inositol ratio choices should follow the evidence rather than marketing; arbitrary ratios are not justified. | Solid | PMID 32308679 |
Short-term effects of metformin and myo-inositol in women with polycystic ovarian syndrome (PCOS): a meta-analysis of randomized clinical trials Facchinetti F, Orrù B, Grandi G, Unfer V · 2019 · Gynecol Endocrinol | SR & meta-analysis | 355 women with PCOS (6 RCTs directly comparing metformin vs myo-inositol) | Metformin vs myo-inositol | Short-term (trials 1994–2017) | No significant difference between metformin and myo-inositol on fasting insulin, HOMA-IR, testosterone or SHBG over the short term — key context for inositol vs metformin comparisons. | Solid | PMID 30614282 |
The Effects of Probiotics or Synbiotics Supplementation in Women with Polycystic Ovarian Syndrome: a Systematic Review and Meta-Analysis of Randomized Clinical Trials Heshmati J, et al. · 2019 · Probiotics Antimicrob Proteins | SR & meta-analysis | Women with PCOS (7 RCTs, 236 women) | Probiotics or synbiotics | Varied | Clinical effect judged negligible and not clearly significant — a second-layer decision, not an automatic add. | Promising | PMID 30547393 |
The 40:1 myo-inositol/D-chiro-inositol plasma ratio is able to restore ovulation in PCOS patients: comparison with other ratios Nordio M, Basciani S, Camajani E · 2019 · Eur Rev Med Pharmacol Sci | RCT | 56 women with PCOS (8 per ratio group) | 2 g of inositols twice daily; seven myo:DCI ratios compared | 3 months | 40:1 performed best for restoring ovulation; shifting the ratio toward more DCI reduced the reproductive benefit. | Solid | PMID 31298405 |
Inositol for subfertile women with polycystic ovary syndrome Showell MG, Mackenzie-Proctor R, Jordan V, Hodgson R, Farquhar C · 2018 · Cochrane Database Syst Rev | Cochrane review | 1,472 subfertile women with PCOS (13 trials) | Myo-inositol, mostly as pre-treatment to IVF | Varied | Evidence rated low to very low quality; authors could not confirm improvements in live birth or clinical pregnancy rates. | Promising | PMID 30570133 |
Insulin-sensitising drugs (metformin, rosiglitazone, pioglitazone, D-chiro-inositol) for women with polycystic ovary syndrome, oligo amenorrhoea and subfertility Morley LC, Tang T, Yasmin E, Norman RJ, Balen AH · 2017 · Cochrane Database Syst Rev | Cochrane review | 4,451 women with PCOS (48 RCTs) | Metformin, clomiphene citrate, rosiglitazone, pioglitazone, D-chiro-inositol | Varied | Metformin may improve live birth vs placebo (low-quality evidence) with more GI side effects. For D-chiro-inositol and the other non-metformin agents, no included studies reported the primary outcomes — no conclusions could be drawn. | Solid | PMID 29183107 |
Myo-inositol effects in women with PCOS: a meta-analysis of randomized controlled trials Unfer V, Facchinetti F, Orrù B, et al. · 2017 · Endocr Connect | SR & meta-analysis | Women with PCOS (9 RCTs; 247 cases, 249 controls) | Myo-inositol alone or combined with D-chiro-inositol | Varied | Meta-analysis of 9 RCTs: myo-inositol (alone or with D-chiro) significantly lowered fasting insulin and HOMA-IR in women with PCOS. Modest sample size. | Solid | PMID 29042448 |
myo-Inositol supplementation and onset of gestational diabetes mellitus in pregnant women with a family history of type 2 diabetes: a prospective, randomized, placebo-controlled study D'Anna R, Scilipoti A, Giordano D, et al. · 2013 · Diabetes Care | RCT | 220 pregnant women with a parent with type 2 diabetes | Myo-inositol 2 g + folic acid 200 mcg twice daily, from the end of the first trimester | Until delivery | Gestational diabetes onset was significantly lower with myo-inositol (6% vs 15% in the placebo group). | Solid | PMID 23340885 |
The combined therapy with myo-inositol and D-chiro-inositol reduces the risk of metabolic disease in PCOS overweight patients compared to myo-inositol supplementation alone Nordio M, Proietti E · 2012 · Eur Rev Med Pharmacol Sci | RCT | Overweight patients with PCOS | Myo-inositol + D-chiro-inositol vs myo-inositol alone | — | Combined myo-inositol + D-chiro reduced the risk of metabolic disease compared with myo-inositol alone. | Promising | PMID 22774396 |
The effect of a combination therapy with myo-inositol and a combined oral contraceptive pill versus a combined oral contraceptive pill alone on metabolic, endocrine, and clinical parameters in polycystic ovary syndrome Minozzi M, Costantino D, Guaraldi C, Unfer V · 2011 · Gynecol Endocrinol | Clinical study (open-label) | 155 women with PCOS | OCP alone vs OCP + myo-inositol 4 g/day | 12 months | Adding myo-inositol 4 g/day to an oral contraceptive improved hirsutism score, reduced hyperinsulinaemia and androgens, and improved the lipid profile vs OCP alone. Open-label design. | Promising | PMID 21417594 |
Myo-inositol rather than D-chiro-inositol is able to improve oocyte quality in intracytoplasmic sperm injection cycles. A prospective, controlled, randomized trial Unfer V, Carlomagno G, Rizzo P, Raffone E, Roseff S · 2011 · Eur Rev Med Pharmacol Sci | RCT | 84 euglycemic women with PCOS undergoing ICSI | Myo-inositol 2 g twice daily vs D-chiro-inositol 0.6 g twice daily | — | More mature oocytes and top-quality embryos with myo-inositol than with high-dose D-chiro-inositol. Caution: the journal issued an Expression of Concern for this paper in 2025 — treat as preliminary. | Preliminary | PMID 21608442 |
Metabolic and hormonal effects of myo-inositol in women with polycystic ovary syndrome: a double-blind trial Costantino D, Minozzi G, Minozzi E, Guaraldi C · 2009 · Eur Rev Med Pharmacol Sci | RCT (double-blind) | 42 women with PCOS | Myo-inositol + folic acid vs folic acid alone | — | Myo-inositol significantly lowered total and free testosterone, triglycerides, blood pressure and the insulin response to oral glucose vs folic acid alone. Small sample. | Promising | PMID 19499845 |
Myo-inositol administration positively affects hyperinsulinemia and hormonal parameters in overweight patients with polycystic ovary syndrome Genazzani AD, Lanzoni C, Ricchieri F, Jasonni VM · 2008 · Gynecol Endocrinol | RCT | Overweight patients with PCOS | Myo-inositol supplementation | — | Myo-inositol improved hyperinsulinemia and hormonal parameters in overweight PCOS. | Promising | PMID 18335328 |
Myo-inositol in patients with polycystic ovary syndrome: a novel method for ovulation induction Papaleo E, Unfer V, Baillargeon JP, et al. · 2007 · Gynecol Endocrinol | RCT (pilot) | 25 women with PCOS-related oligo/amenorrhea | Myo-inositol (per trial protocol) | — | In a small pilot study, myo-inositol restored ovulatory function in most participants with PCOS-related oligo/amenorrhea. Small sample — promising, not definitive. | Promising | PMID 17952759 |
Ovulatory and metabolic effects of D-chiro-inositol in the polycystic ovary syndrome Nestler JE, Jakubowicz DJ, Reamer P, et al. · 1999 · N Engl J Med | RCT (double-blind, placebo-controlled) | 44 obese women with PCOS | D-chiro-inositol 1,200 mg once daily vs placebo | 6–8 weeks | Landmark trial: 19 of 22 women ovulated on D-chiro-inositol vs 6 of 22 on placebo (P<0.001). Insulin AUC fell substantially, free testosterone dropped, and blood pressure and triglycerides improved. A foundational study, though note it used DCI monotherapy at 1,200 mg — a dose and format most modern products do not replicate. | Solid | PMID 10219066 |
This database is a desk-research summary of peer-reviewed sources (PubMed/PMC), maintained under our editorial policy. It does not replace professional medical advice. Studies are classified by how much the evidence supports the claim: solid, promising but limited, or preliminary.