Inositol is a natural compound found in plants, animals, and humans and it has nine stereo-isomers, which is the techy way of saying it comes in nine near-identical forms. Inositol has a number of important roles in the body, and probably some that we don’t know about yet. One of the roles is as a secondary messenger in the central nervous system, influencing neurotransmitters and mood for some people. Another role is to increase insulin sensitivity, and this is especially important in insulin resistance, type 2 diabetes and polycystic ovary syndrome (PCOS).
PCOS
PCOS is not just one uniform syndrome, with all women having the same causes and signs and symptoms; instead it is varied between women. That said, for most women with PCOS, insulin resistance appears to play a role in the development of PCOS and reducing insulin resistance is important in managing PCOS. Inositol is an insulin-sensitiser, meaning the cells of the body are more sensitive to (thus use) insulin allow glucose into the cells. Interestingly, inositol helps establish normal ovulation in women with PCOS even if they don’t have insulin resistance (shows there is more we have discover and learn).
For more on PCOS see here and here.
Some of the benefits of inositol for women with PCOS include:
- reduced insulin resistance/improved insulin sensitivity
- reduced androgen levels (e.g. testosterone)
- increased sex-hormone binding globulin (SHBG), which is typically low in PCOS
- increased progesterone (primarily due to ovulating again)
- reduced lutenising hormone (LH), which is high in PCOS
- restoration of regular ovulation
- more regular periods
- improved fertility
- improved oocyte and embryo quality (including improved oocyte maturation in IVF)
- reduced ovarian hyperstimulation syndrome in IVF
- reduced blood glucose and HbA1c
- reduced long-term risks of untreated PCOS such as cardiovascular disease and metabolic syndrome
- reduced PMS symptoms
- improvements in anxiety and depression
Some research has shown additional improvements when the inositol was combined with melatonin or folic acid and n-acetylcysteine (NAC). Further, most research has used the myo-inositol form, with a smaller number using a combination of myo-inositol and D-chiro-inositol.
How good is it?
Some research indicates that it is more effective in restoring normal ovulation and improving pregnancy outcomes than Metformin, which is the most commonly prescribed medication for PCOS and insulin resistance.
Thyroid
One last point – inositol has also recently been found to improve thyroid function, including in Hashimoto’s Disease, and up to 40% of women with PCOS also have Hashimoto’s.
Food sources of inositol
Inositol is found in many foods, however it can be tricky to get an adequate amount for it to be therapeutic. Studies on inositol and PCOS have been on supplementation with inositol, not from food alone, however I think it can be helpful to have some of the food source as well for the possible synergies in the whole food source that we just don’t know about.
Food sources include:
- Brazil nuts, almonds, walnuts,
- rockmelon, citrus fruits, peaches, pears, bananas
- whole grains, bran, oats
- beans, peas, capsicum, tomatoes, potatoes, asparagus, green leafy vegetables
- beef, eggs
- coconut products
Supplementation with inositol
It is recommended that you consult with a nutritionist or naturopath before commencing any new supplement.
Inositol is available as a powder and it has little taste and appears to only have side effects (digestive upset) at very high doses (much higher than the recommended dosage).







