Short answer: Inositol, especially myo-inositol (sometimes combined with D-chiro-inositol), is one of the most studied supplements for PCOS. Research suggests it can improve insulin sensitivity, lower testosterone levels, and make menstrual cycles more regular. However, the international PCOS guidelines (2023) emphasize that evidence for actual pregnancy outcomes is limited. Lifestyle is the foundation.
What is inositol?
Inositol is a naturally occurring substance similar to a B vitamin that plays a role in cellular insulin signaling. The two forms most relevant for PCOS are myo-inositol and D-chiro-inositol.
Why inositol for PCOS?
In PCOS, insulin resistance is often a central mechanism, contributing to high levels of male sex hormones and irregular or absent ovulation. Since inositol is involved in insulin signaling, researchers have investigated whether it can improve these specific aspects.
What does the research say?
Systematic reviews have found that myo-inositol can improve insulin values, lower testosterone, and to some extent make menstrual cycles more regular, with a mild side effect profile. However, in the systematic review that formed the basis for the 2023 international PCOS guidelines, the evidence was deemed limited, especially for pregnancy and live birth, and inositol is not recommended as a standalone fertility treatment. The conclusion is: promising as a complement, but not decisive.
Myo- or D-chiro-inositol?
Myo-inositol is the most studied form. A combination in a 40:1 ratio (myo:D-chiro), which mimics the body's natural balance, is also used in studies and products.
Dose and safety
Studies have often used about 2 grams of myo-inositol twice daily. Inositol is generally considered safe and well-tolerated. Nevertheless, discuss it with your doctor, especially if you are being treated for PCOS or undergoing fertility treatment.
Frequently Asked Questions
Will inositol help me get pregnant?
Possibly as part of a comprehensive approach, but it is not a guaranteed or standalone treatment. Discuss with your healthcare provider.
How long does it take?
Studies have often lasted three to six months before effects on cycle and ovulation were observed.
This article provides general information and does not constitute medical advice. Consult a doctor for PCOS and desired pregnancy.
Sources
- J Clin Endocrinol Metab (2024). Inositol for Polycystic Ovary Syndrome: A Systematic Review and Meta-analysis (2023 guideline update).