Let’s talk: Inositol

Inositol, or more precisely myo-inositol, is a type of sugar with some very important functions in the body with the regulation and processing of insulin, cholesterol, anxiety and depression. 

As a supplement, inositol can be helpful for a range of conditions, including PCOS (insulin resistance), type 2 or gestational diabetes, insulin resistance, metabolic syndrome, PMDD, depression and OCD.

What is inositol?

Inositol, sometimes referred to as vitamin B8, is a type of sugar that acts as an antioxidant in the body. Confusing much?! It is mostly found in the heart and brain and is involved in messenger pathways between the cells. 

When looking at insulin resistance, type 2 diabetes, gestational diabetes, PCOS (insulin resistant) and metabolic syndrome, inositol improves glucose regulation through increased insulin sensitivity. In mental health conditions, inositol stimulates the production of various neurotransmitters by increasing the levels of the hormones that turn into neurotransmitters. If we think of neurotransmitters like a cake, with more ingredients we can make more cake!

Sources of inositol

Inositol can be found in cantaloupe, citrus fruit, and many fibre-rich foods (such as beans, brown rice, corn, sesame seeds, and wheat bran), or made in a laboratory.

What does the research say?


Inositol is involved in the signalling pathways which positively affect conception. Particularly, myo-inositol could prevent the onset of neural tube defects and the occurrence of gestational diabetes, reducing complications in pregnancy. It also increases egg (oocyte) quality and supports the progression of the early stages of pregnancy. Inositol can also be used to induce ovulation, which increases the likelihood of conception. Currently, the research demonstrates supplementing with myo-inositol in the preconception period enhances the probability of achieving pregnancy and reduces the onset of adverse maternal effects and neonatal outcomes.


Research published in 2016 showed inositol is as effective as metformin in improving the symptoms of PCOS when one group with PCOS was given metformin and another was given inositol. Both treatments have similar effects in inducing weight loss. Because of metabolic changes, the menstrual cycle length improved in approximately 80% of women, with a complete restoration of a normal menstrual cycle in about 50% of the patients. Along with being better for reproductive health, this increases chances of conception if you’re trying to conceive. The administration of metformin is associated with side effects that are not experienced with inositol, making inositol a favourable option. 


In 2011, a two-stage study established the efficacy of inositol for PMDD. Results clearly showed that Myo-inositol could reduce several aspects of PMDD syndrome, including symptoms of depression. All scores improved in the Myo-inositol treated groups compared with the baseline and the placebo.

Gestational diabetes

A study in 2017 identified people at risk of gestational diabetes and put them into 4 groups: Myo-inositol, d-chiro-inositol, combined Myo- and d-chiro-inositol or a placebo. The group of women allocated to receive Myo-inositol alone had a lower incidence of abnormal oral glucose tolerance test (OGTT).


Missing periods or amenorrhea is caused by a lack of ovulation, as no oocyte is released during the menstrual cycle. Where there are irregular periods without PCOS, this is often due to a hormonal imbalance reducing the level of follicular stimulating hormone (FSH ). Therefore, follicular growth doesn’t happen, and there’s no egg to release as part of the cycle. Inositol (particularly d-chiro-inositol) can help to rebalance these hormones and induce ovulation in 6 weeks.


Inositol has a role in the signalling and messaging pathways of many hormones, including thyroid hormones like thyroid stimulating hormone (TSH).  Inositol is essential to produce compounds required for the production of thyroid hormones and consequently, not having enough inositol can lead to hypothyroidism. Many clinical studies support the supplementation of inositol with selenium to treat subclinical hypothyroidism with or without autoimmune thyroiditis.

When to take inositol

Inositol can be taken once or twice a day. It comes in a powder that can be compounded with other supplements. Dosages do vary depending on the issue you’re trying to address, so it’s best to talk with a practitioner to make sure you’re taking the therapeutic dose. 

Some medications will deplete stores of inositol. These include lithium, valproate and carbamazepine (Tegretol). If you’re taking these medications, it could be recommended to take some inositol to counteract the effects of the medication. Once again, dosages are individualised, so please talk to a practitioner before taking any supplements.

Interactions with other nutrients

Inositol doesn’t interact with other nutrients, but it can interact with other medications, so make sure you check with your practitioner before taking inositol. 

If you’re interested in taking any supplements, please discuss this with your practitioner to ensure you’re taking the correct dose and form for you. This article is not intended to be medical advice and is purely for education purposes.