Inositol → Insulin resistance (HOMA-IR)
Higher Inositol decreases Insulin resistance (HOMA-IR).
Giordano 2011 found that 2 g of myo-inositol twice a day plus diet for six months lowered the HOMA insulin-resistance index versus diet plus placebo in 80 postmenopausal women with metabolic syndrome. D'Anna 2015 saw a smaller HOMA drop and less gestational diabetes in 220 obese pregnancies; that file was open-label.
Randomized trial · Contested · N=80
Supported by an experiment or a tightly identified design. Read the caveats.
Mechanism
Authors treat myo-inositol as an insulin sensitizer. They do not isolate one isomer as the only actor. Giordano, Corrado, Santamaria and colleagues assigned 80 postmenopausal women with metabolic syndrome to diet plus 2 g twice a day or diet plus placebo for six months. HOMA, blood pressure, cholesterol, and triglycerides moved versus placebo. The abstract reports a 75 percent HOMA drop on inositol. D'Anna, Di Benedetto, Scilipoti and colleagues assigned 220 obese pregnant women to 2 g myo-inositol plus folic acid twice a day or folic acid alone from the first trimester. Open-label. Gestational diabetes was 14.0 percent versus 33.6 percent (P=0.001). HOMA changed -1.0 versus +0.1 (P=0.048). Formuso, Stracquadanio and Ciotta assigned 137 women with polycystic ovary syndrome to myo-inositol, D-chiro-inositol, or placebo for six months. Both inositol arms improved cycle regularity, acne score, and insulin resistance.
Caveats
Researchers assigned people to a powder or a control, so this is a trial stamp. Populations split. More papers of the same design do not settle the claim. Giordano's 75 percent HOMA drop is one postmenopausal file. D'Anna is open-label pregnancy. Formuso is a three-arm PCOS file without a published HOMA increment in the abstract. This is a journal entry, not medical advice and not a reason to take inositol for insulin resistance.
Effect
qualitative. Giordano 2011: 2 g BID + diet vs diet+placebo, 6 mo, N=80 postmenopausal MetS, HOMA -75%. D'Anna 2015: open-label, N=220 obese pregnancy, HOMA -1.0 vs +0.1. Formuso 2016: N=137 PCOS vs placebo.
Nodes
Named confounders
Cite this page
What Causes What. “Inositol → Insulin resistance (HOMA-IR).” https://whatcauseswhat.org/edges/e-inositol-insulin (atlas updated 2026-09-02).
Papers
- Effects of myo-inositol supplementation in postmenopausal women with metabolic syndrome: a perspective, randomized, placebo-controlled study.
D Giordano, F Corrado, A Santamaria, S Quattrone, B Pintaudi, A Di Benedetto, R D'Anna · 2011 · Menopause (New York, N.Y.)
- Myo-inositol Supplementation for Prevention of Gestational Diabetes in Obese Pregnant Women: A Randomized Controlled Trial.
R D'Anna, A Di Benedetto, A Scilipoti, A Santamaria, ML Interdonato, E Petrella, I Neri, B Pintaudi · 2015 · Obstetrics and gynecology
- Myo-inositol vs. D-chiro inositol in PCOS treatment.
C Formuso, M Stracquadanio, L Ciotta · 2016 · Minerva ginecologica