Myo-inositol
Myo-inositol is a natural sugar that the body makes and that we also get from food (fruit, pulses, cereals).
2–4 g a day.
What it is
It is part of cell membranes and is involved in how cells respond to insulin, which explains the interest in it for the menstrual cycle and hormonal balance.
What it is used for
The quiz suggests it when your answers justify it. It usually appears with these goals:
What the evidence says
Trials in people that point the same way, but still few, small or funded by the manufacturer.
Several trials in women with irregular cycles show improvements in regularity and insulin sensitivity, but the international guidelines (2023) still consider it under investigation.
| Year | What was studied | What was found | Source |
|---|---|---|---|
| 2017 | Metabolic and hormonal | Meta-analysis of 9 RCTs (496 women with PCOS): it reduced fasting insulin. Testosterone only showed a downward trend, and SHBG rose in studies lasting 24 weeks or more. (One of the authors works for an inositol manufacturer.) | Unfer et al.Endocrine Connections |
| 2018 | Ovulation and cycle | Independent meta-analysis of 10 RCTs: it seems to regulate menstrual cycles and improve ovulation, although data on pregnancy and live births are lacking. | Pundir et al.BJOG |
| 2024 | The official caution | Meta-analysis informing the 2023 international PCOS guidelines: the evidence is still limited and inconclusive, and it recommends deciding case by case. | Fitz et al.Journal of Clinical Endocrinology & Metabolism |
What to look for on the label
- Pure myo-inositol powder; if combined, a 40:1 ratio with D-chiro-inositol.
Precautions
- High doses can cause mild digestive discomfort.
- If you take medication for blood sugar, ask first.
Where to find it
Products whose label meets what this profile asks for: form, dose per serving and nothing that contradicts it. Three at most: quality of the active comes first and, among the best, we look for one option in each price range. We choose by composition, not by who pays. The shops are European or ship to Europe.
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Life ExtensionShips from the Netherlands€€€High endLife Extension
Inositol 1,000 mg
1 g per capsule
For the reference dose2–4 capsulesView at Life Extension (opens in a new tab)Meets the criteria.
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VegaveroShips from Germany€€Mid rangeVegavero
Myo-inositol powder
Pure myo-inositol, 1 g per scoop
For the reference dose2–4 scoops (2–4 g)View at Vegavero (opens in a new tab)Meets the criteria.
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HSNShips from Spain€BudgetRaw Series
Inositol powder
Pure myo-inositol
For the reference dose2–4 gView at HSN (opens in a new tab)Meets the criteria.
We link to the shop; we do not sell anything. Today we earn no commission on any link. If we ever do, the link will say so and the selection will not change: the label decides. Labels checked on 2 November 2026; check the one on the pack before you buy. All these shops deliver to the EU; some of their pages open in Spanish. How we are funded.
Nearby in the library
Is it for you?
The quiz decides from your answers, not from a profile.
Profile reviewed on 3 November 2026. Sources: EFSA, Regulation (EU) 432/2012 and published studies. Image: Chemical apparatus. Engraving by J. Pass, 1801. Wellcome Collection, public domain.
General information based on published scientific evidence and EU law. Food supplements should not be used as a substitute for a varied, balanced diet and a healthy lifestyle, and are not intended to diagnose, treat or prevent any disease.
Do not exceed the daily dose stated on each product. If you take medication, have a medical condition or have any doubts, ask your doctor or pharmacist.