4 Things to Know About Taking Inositol for PCOS

Certain types of inositol are showing promise as a primary treatment for women with polycystic ovary syndrome, or PCOS. Inositols are carbohydrates that can influence the body's insulin response, and when taken as a supplement may help improve metabolic and reproductive aspects of PCOS.

Possible Benefits of Inositol Supplements for PCOS Treatment

Laura Porter / Verywell

Inositols and PCOS

While the research is promising, it's important to understand the basics of inositol as it applies to PCOS. Here’s what to know, but remember to speak to your doctor before taking any supplements.

Inositols such as myo- and d-chiro inositol (DCI) are considered members of the B-vitamin group, but are in fact carbohydrates (sugars) that also possess antioxidant properties. Inositol is found in healthier foods such as fruits, beans, grains, and nuts, though it is also made by the body.

Myo and DCI work as secondary messengers relaying signals involved in insulin regulation. It is believed that women with PCOS may have a defect in the body’s ability to convert myo into DCI, which contributes to insulin resistance and infertility.

Supplementing with inositol is well tolerated (no gastrointestinal side effects like those associated with metformin) and has been shown to improve insulin levels and reduce intense cravings.

Combining Myo and D-Chiro Inositols

Newer research into the effects of inositol have revealed the majority of tissues in the body have a ratio of myo to DCI of approximately 40:1. Taking a combination of these two supplements in this ratio rather than just taking myo or DCI alone is recommended.

When compared to myo-inositol, women with PCOS experienced more benefits relating to metabolic parameters (lowering insulin, cholesterol, and inflammatory markers) when they took a combination of myo and DCI.

When compared with metformin, a combination of myo and DCI in a 40:1 ratio showed significantly better results in regards to weight loss, ovulation, and pregnancy rates (46.7% vs.11.2%).

Inositol Ratio Affects Egg Quality and Fertility

An imbalance in the body’s physiological ratio of myo to DCI ratio can affect egg quality. Myo-inositol has been shown to improve egg quality in women with PCOS whereas DCI administered at high dosages (600 to 2400 mg daily) was found to negatively affect oocyte quality (cells in the ovary that could become eggs) and ovarian response.

What’s more, the higher the dose of DCI (and the more imbalanced the ratio of Myo to DCI), the worse the oocyte quality and ovarian response became.

Inositol and Gestational Diabetes

It has been suggested that women with PCOS may be at an increased risk for gestational diabetes mellitus (GDM) in pregnancy.  Studies have shown that supplementing with myo-inositol throughout pregnancy can be effective in reducing the risk for GDM in both overweight women and women with PCOS.

A study in Gynecology Endocrinology showed the prevalence of GDM among pregnant women with PCOS who took myo-inositol group was 17.4% versus 54% in the control group.

A Word From Verywell

Research supports the use of combinations of inositol supplements in relation to PCOS. If you have the condition, it's worth a conversation with your doctor to see if it could benefit you. Remember, it's not a good idea to try inositol supplementation without medical guidance, particularly when attempting a combination of myo-inositol and DCI.

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