Inositol is one of the more-studied supplements for PCOS — evidence is moderate and mixed
🌸 PCOSBy the Bloom Health Woman editorial team · Last updated October 2026 · Educational information, not medical advice. This page contains an affiliate link (see the product box). How we create content
Inositol (myo-inositol, sometimes with D-chiro-inositol) is involved in insulin signalling. Several randomized trials in people with PCOS suggest it may improve some insulin, hormone and ovulation-related measures, but studies differ in design and quality, and guideline groups describe the evidence as limited. It is not proven to be as effective as prescription treatments and does not treat PCOS.
People with PCOS who are discussing options with a clinician. Whether it suits you depends on your health, medicines and test results — ask a clinician.
Trials have commonly used about 2–4 g of myo-inositol daily, sometimes combined with D-chiro-inositol in a 40:1 ratio, in two divided doses. This is not a recommendation. Doses vary by product and person; this is not personal medical advice.
Studies reported changes after about 3–6 months in some participants; many see no change.
Nausea, gas, stomach upset or loose stools, mainly at higher doses.
Ask your doctor first if you are pregnant, breastfeeding or taking diabetes medicines. Do not replace prescribed PCOS treatment with a supplement.
Evidence level (our editorial summary, not a formal grading): Moderate (mixed quality).
Pregnancy & breastfeeding: Safety data at high doses in pregnancy are limited; discuss with your provider.
Medication interactions: May affect blood sugar; discuss with your doctor if you take diabetes medicines or metformin.
Talk to a healthcare professional before use if you are pregnant, breastfeeding, planning pregnancy, have a medical condition, take any medicine, or are scheduled for surgery. Dietary supplements are not approved by the FDA for safety or effectiveness before they are sold, and quality varies between products.
Reliable sources to check: NIH Office of Dietary Supplements fact sheets · NCCIH Herbs at a Glance · MedlinePlus Herbs & Supplements · FDA — Dietary Supplements
Optional product link. We have not tested this product and its inclusion is not a medical recommendation or an endorsement of any brand.
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