Inositol is suggested to be a helpful supplement for PCOS, mental health, periods, and more. Let’s break down the facts about this naturally occurring substance. 


By fertility expert and OBGYN Dr. Kenosha Gleaton

True or false: there’s one supplement that has shown improvements in mental health, ovulatory function, PCOS, fertility, and more… true! Inositol is a carbohydrate that interacts strongly with hormones and neurotransmitters in the body. More research is needed, but here’s what we know so far. 

What is inositol?

Inositol is a naturally occurring, vitamin-like carbohydrate that’s found in your body. It’s most abundant in the brain and tissues and has a large effect on hormones and other  neurotransmitters. 

Inositol is frequently used for metabolic syndrome and polycystic ovary syndrome (PCOS), as well as other medical and mental conditions. There are many forms of inositol, but the two most common are myo-inositol (MI) and D-chiro-inositol (DCI). 

Inositol and periods

Inositol has been shown to help regulate menstrual cycles and improve ovulatory function. A randomized, double-blind clinical trial found a beneficial effect of Myo-Inositol in improving function in women with oligomenorrhea (aka infrequent menstrual periods). The study also found that women who took myo-inositol ovulated more frequently than those in the placebo group.

Inositol and PCOS

The same clinical trial discovered that Myo-Inositol improves ovarian function in women with polycystic ovaries (a hormonal disorder causing enlarged ovaries with small cysts). Inositol is also used to improve glucose levels and insulin resistance. This is helpful for those with PCOS, as insulin resistance is found in 30-40% of patients. While using inositol to manage PCOS remains experimental, many studies suggest inositol can decrease insulin resistance, improve ovarian function, and reduce androgen levels.

Inositol and egg quality

There have been established antioxidant and growth-promoting factors of MI. Some studies have shown improved embryo and oocyte quality as well as improved overall ovulary function as a result of MI supplementation. The ovary also uses high levels of MI to help carry out physiological activities and is thought to increase insulin sensitivity of the ovary to potentially improve egg quality. 

Inositol and mental health

Only small studies have been done to research inositol’s role in mental illness, but so far it has been linked to reduced depression, hostility, tension, and fatigue. A double-blind controlled trial studying the role of inositol in psychiatry found that  MI supplementation may have therapeutic effects for some mental illnesses, but not all. Specifically illness related to serotonin selective reuptake inhibitors, such as depression, panic, and OCD. 

Inositol and gestational diabetes

As previously mentioned, inositol is known to be useful for glucose homeostasis. Gestational diabetes can be difficult to treat with insulin and other oral medications due to side effects, therefore more research is being focused on inositol supplementation. Current evidence shows that MI may help reduce the risk of GDM among overweight pregnant women, although more studies are needed to evaluate effectiveness. 

Inositol and blood sugar

Inositol shows positive effects for insulin function during pregnancy and beyond. Combined MI and DCI supplementation impacts neurotransmitters in the body and has been shown to improve insulin function and reduce blood glucose rise. A pilot study concluded that inositol supplementation is an effective and safe strategy for improving glycemic control in type 2 diabetes. 

Inositol and cholesterol

A systematic review found that inositol supplementation may result in a reduction of triglycerides, total, and LDL-cholesterol (low density) levels, but does not affect HDL-cholesterol (high density) levels. More research is still needed to examine the full effect of inositol supplementation on lipid profiles in patients with metabolic diseases.

What foods include inositol?

Inositol is present in fruits, beans, grains, and nuts, specifically corn, cantaloupe, citrus, sesame seeds, and wheat bran. Fresh vegetables and fruits contain more myo-inositol than frozen, canned, or salt-free products.

Inositol supplementation

It’s important to note that there are actually nine different types, or isomers, of inositol. The main difference between isomers of inositol is in the function of the various compounds. While there isn’t a “best” form of inositol, there are different functions, and getting the most out of supplementation means determining what ratio of MI:DCI will be most effective for you.

When mimicking inositol function for reproductive processes,  clinical evidence has demonstrated that a 40:1 ratio between MI and DCI is the optimal combination for the most effective results.

Risks of inositol supplementation

All studies mentioned found little to no negative side effects from taking inositol supplements, and there are no known negative interactions with other supplements or medications. Like most medications, there is a risk of an upset stomach. While inositol supplementation shows many benefits, it shouldn’t be used as a replacement for any current medications without talking to your doctor first.


  • Inositol is a naturally occurring substance that may be useful for treating a wide range of conditions and symptoms, including PCOS, irregular menstrual cycles, gestational diabetes, and more. 
  • Inositol works by interacting with hormones and neurotransmitters in the body.
  • There are nine different types of inositol, but the most common and effective type is a 40:1 ratio of myo-inositol (MI) and D-chiro-inositol (DCI).
  • Inositol has been shown to improve ovulatory function, glucose function, insulin resistance, and egg quality, and reduce depression, hostility, triglycerides, and LDL cholesterol. 
  • Inositol can be found naturally in citrus fruits, cantaloupe, grains, and nuts.


Featured Image by Alice Castro