5 Things to Know About Taking Inositol for PCOS

Women with polycystic ovary syndrome, or PCOS, have a hormone imbalance. This can lead to several health problems, including diabetes and infertility. Treatment with vitamin-like substances called inositols has shown promising results.

Read on to learn more about inositol supplements and how they may help women with PCOS control their blood sugar and get pregnant.

Possible Benefits of Inositol Supplements for PCOS Treatment

Verywell/Laura Porter

Inositols and PCOS

Inositols are a kind of sugar the body makes. They help balance chemicals that control your mood swings, blood sugar, fertility, and metabolism, the process of turning the food you eat into energy.

Many women with PCOS are insulin resistant. Their bodies make insulin but aren't able to use it effectively. This increases their risk of diabetes, infertility, obesity, and high cholesterol levels.

Inositols make molecules involved in the body's response to insulin. Researchers say inositols can be used as a backup messaging system when the usual insulin signaling system fails.

You can get inositols by eating healthy foods such as:

Fruits: Cantaloupe, grapefruit, other citrus fruits

Beans: Lima, navy

Grains: Brown rice, whole wheat

Nuts: Almonds, walnuts

You can also buy inositol food supplements, pills, or powders you mix with water. Most people tolerate inositols well.This is important because the diabetes drug doctors often use to treat PCOS, Metformin, is associated with side effects such as diarrhea, stomach pain, and nausea.

There are nine inositols. The two that appear to benefit women with PCOS are myo-(MI) and d-chiro (DCI). Both are important to the body's response to insulin. MI also helps control hormones needed for egg production in the ovaries. DCI also helps control male hormone levels in women.

99% of inositols in the body are MI, but a certain level of DCI is needed for a healthy balance. Researchers believe many women with PCOS are less able to convert MI into DCI. Lower levels of DCI within the body's tissues increase the risk of insulin resistance and high blood sugar levels.

Ratio Lowers Blood Sugar, Cholesterol and Improves Fertility

In the past, researchers have tried to prove that either MI or DCI was better for treating PCOS. Several recent studies have shown that using a combination of MI and DCI can help improve insulin sensitivity and restart ovulation.This is the part of a woman's monthly cycle where an ovary releases an egg.

Researchers know that in healthy women, most body tissue has an MI to DCI ratio of approximately 40-to-one. In many women with PCOS, this ratio is much higher.

Studies using treatments with a 40-to-1 MI to DCI ratio have shown it is the most helpful in improving fertility rates in women with PCOS. However, food supplement companies sell remedies with varying inositol ratios. One recent review study found that the MI to DCI ratio in PCOS products can range from as little as .04-to-1 to as high as 104-to-1.

Some remedies contain only DCI. Others add vitamins, artificial sugars, and other substances. There's no evidence to show these ingredients help. In fact, some artificial sugars like sucralose (Splenda) and sugar alcohols like sorbitol (found in sugar-free candy and chewing gum) can make the treatment less effective.That's because they prevent the small intestine from absorbing MI.

Another study found that compared with the prescription diabetes drug Metformin, women who took the 40-to-one MI to DCI ratio had significantly better weight loss, ovulation, and pregnancy rates (46.7% vs.11.2%).

Ratio Improves Periods, Ovulation, and Egg Quality

PCOS is the most common cause of infertility, affecting up to 12% of women.Symptoms often begin with the first period. Levels of MI and DCI in the tissues differ from levels in some organs. Women with PCOS have an imbalance of their MI to DCI ratio within their ovaries. This can affect their:

Periods: Women with PCOS can have no periods at all or irregular ones. Treatment with inositols have been shown to help improve insulin sensitivity and reduce male hormone levels like testosterone in women with PCOS.This helps restore periods.

Ovulation: Women with PCOS might not ovulate every month or at all. Researchers have linked this to having too little MI and too much DCI levels within the ovaries.

Egg quality: Women with PCOS have been shown to produce less mature eggs than women without the disorder (13.8% to 5.8%, respectively). Researchers have linked this to having too little MI in the follicular fluid which surrounds the eggs within the ovaries.

For healthy eggs to mature, a high level of MI is needed within the follicular fluid.In healthy women, the MI to DCI ratio in this fluid is about 100-to-one. However, in infertile women with PCOS, the average ratio of MI to DCI in this fluid is 0.2-to-one.

Treatment with inositols can help restore ovulation and improve egg quality. However, researchers warn using the correct formula is essential. High doses of DCI have been shown to negatively affect cells in the ovaries that could become eggs. Too high a dose of DCI can also prevent the body from absorbing MI.

MI Used to Treat Gestational Diabetes

Women with PCOS are four times more likely to develop diabetes than women who don't have the disorder.They also have an increased risk of gestational diabetes, (GD) which occurs during pregnancy. One study estimated that the risk is nearly 20% greater.

Researchers have shown that taking MI supplements can lower blood sugar levels and GD risk in overweight women and women with PCOS.

A study in Gynecology Endocrinology showed the number of cases of GD among pregnant women with PCOS who took MI was 17.4% versus 54% in those who didn't.


Inositols are sugars the body makes that help regulate insulin and cholesterol levels. Two types of inositols are helpful for treating women with PCOS, MI and DCI.

You can get inositols by eating certain foods or taking food supplements. Studies suggest that if you're struggling with infertility, a 40-to-1 MI to DCI ratio appears to be the most helpful. This ratio has also been shown to help lower insulin and cholesterol levels in women with PCOS.

A Word From Verywell

Research into using combinations of inositol supplements to treat women with PCOS is very promising. It's also exciting because it's inexpensive compared to some other infertility treatments. If you have PCOS, you may want to ask your healthcare provider if it could benefit you.

You may feel tempted to try using inositol supplements on your own. That's not a good idea. Taking too much DCI, for example, can lower your estrogen levels and increase male hormone levels. Estrogen provides several benefits like protecting bones and preventing breast cancer. Increasing testosterone levels in women already at risk of infertility also isn't wise.

If your healthcare provider agrees and you decide to try inositols, you may need to be extra careful of what you eat and drink. Some artificial sugars and sugar alcohols weaken the benefit of these supplements.

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18 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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