Metabolic & Cardiometabolic
inositol decreases insulin resistance
Leans support Metabolic & Cardiometabolic 🔬 Includes disconfirming
RefutedContestedStrong support
consensus score 0.28
📅 Last reviewed: 2026-07-15 ⓘ
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: All trials, pooled (Meta-analysis)
MechanismIn-vitroAnimalObservationalRCTMeta-analysis
How the studies fall
2 support 1 contradict 1 tested null 1 mixed · 5 sources, 3 independent groups
What the evidence shows
Inositol (myo-inositol / D-chiro-inositol) improves insulin resistance / metabolic measures in PCOS.
The evidence (7)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Mashhadi F, Ghaebi NK, Rakhshandeh H, Khadem-Rezaiyan M, Roudi F, Nematy M 2026 · Journal of ovarian research | RCT | tested-null | low | n=196 infertile PCOS, 4-arm 12wk (metformin/MI 2000mg/Ziziphus/placebo): significant FBG/lipid/TyG gains reported for Ziziphus arm; myo-inositol arm's own metabolic advantage over placebo not distinctly reported |
| Bahadur A, Arora H, Ravi AK, Naithani M, Bahurupi Y, Chaturvedi J, Ajmani M, Mundhra R 2021 · Cureus | RCT | contradicts | moderate | Non-blinded RCT, n=72 analysed (per-protocol), newly diagnosed PCOS, 6 months: metformin 500 mg bid vs metformin + MI 550 mg + DCI 150 mg bid (inositol randomised as add-on). End-of-treatment HOMA-IR 3.23 vs 3.08 (p=0.746) and fasting insulin 15.04 vs 14.68 mIU/L (p=0.858): 'No significant difference was seen between the two groups in terms of ... fasting insulin and homeostatic model assessment of insulin resistance (HOMA-IR) index.' Null on the claim's IR index, so contradicts. Two-hour postprandial insulin was lower with inositol (57.82 vs 35.30 mIU/L, p=0.005) with postprandial glucose unchanged; authors note 'a small sample size'. |
| Duan M, Yang M, Li C, Wu X, Yin X, Zhu H 2026 · Frontiers in endocrinology | meta-analysis | supports | moderate | Umbrella review, units are syntheses: 'Thirteen meta-analyses were included.' 'This study aims to provide a descriptive synthesis and quality assessment of existing evidence rather than conduct a new meta-analysis.' 'All pooled effect sizes were derived from a secondary synthesis of relevant meta-analysis results' (HOMA-IR MD -1.14, -1.35 to -0.94). Review — zero weight. |
| Fitz V, Graca S, Mahalingaiah S, Liu J, Lai L, Butt A, Armour M, Rao V, Naidoo D, Maunder A, Yang G, Vaddiparthi V, Witchel SF, Pena A, Spritzer PM, Li R, Tay C, Mousa A, Teede H, Ee C 2024 · J Clin Endocrinol Metab | meta-analysis | mixed | moderate | 30 trials (n=2230): myo-inositol/DCI may improve SOME metabolic measures, DCI maybe ovulation, but no effect on other outcomes; low GRADE certainty. Authors' explicit verdict: limited and inconclusive. |
| Tienforti D, Puocci G, Venditti C, Gizzi V, Pisanò C, Cocci E, Perfetto E, D'Alessandro F, Spagnolo L, Baroni MG, Barbonetti A 2026 · Clin Endocrinol (Oxf) | meta-analysis | mixed | moderate | The meta-analysis pools no insulin-resistance outcome. 'Primary outcomes were serum total testosterone (TT), calculated free testosterone (cFT), free androgen index (FAI), and sex hormone-binding globulin (SHBG). Prespecified subgroup analyses explored differences according to body mass index (BMI) and insulin resistance (HOMA-IR).' HOMA-IR is a stratifier, not an outcome. What the paper found, on androgens, across 9 RCTs and 440 women with PCOS: 'Inositol supplementation was associated with significant reductions in TT (SMD -1.30; 95% CI -2.17 to -0.42), cFT, and FAI, together with an increase in SHBG', with 'Substantial heterogeneity ... observed for several outcomes'. CORRECTION to the previous extract, which read 'NO sig HOMA-IR improvement in women with IR analyzed independent of BMI': the paper reports no pooled HOMA-IR result. The sentence that was paraphrased -- 'No significant improvements were detected in overweight or obese women, nor in women with insulin resistance when considered independently of BMI' -- sits in the RESULTS paragraph about total testosterone and refers to ANDROGEN improvements within an insulin-resistant subgroup. Outcome and moderator were transposed. Abstract-grade read; Europe PMC full text for PMC13326987 returned empty. |
| Delavar MA, Mirabi P, Rosenkranz SK, Alibabaei-Omran F, Ahmadi N, Ghorbani Z 2025 · Diabetology & metabolic syndrome | meta-analysis | supports | moderate | 18-RCT cardiometabolic MA (NOT PCOS-restricted): significant HOMA-IR/glucose/insulin reductions but I2=85-91% (very high heterogeneity), moderate GRADE. Off-scope population + heterogeneity -> low weight. |
| Gul M, Khan H, Rauf B, Bukhari SMS, Ehtesham E, Malik MO, Shah FA, Alanazi FE, Shah M 2025 · Naunyn Schmiedebergs Arch Pharmacol | RCT | supports | moderate | MI+DCI 40:1 improved HOMA-IR (p<0.001), SHBG (p=0.021), ovarian volume, menses — but metformin slightly superior. |
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