Inositol

Last Updated: November 14 2022

Inositol refers to a group of molecules that are involved in various regulatory and metabolic processes. The most commonly supplemented forms of inositol are Myo-inositol and D-chiro-inositol, but all forms are interchangeably referred to as inositol. It’s best known for its effects on insulin resistance and is often supplemented in the context of polycystic ovarian syndrome (PCOS).

Inositol is most often used for

What is inositol?

Inositol refers to a group of molecules that are structurally similar to glucose and are involved in cellular signaling. A majority of inositol supplementation uses the myo-inositol form, as it is the most plentiful type of inositol found in the body.[90] Low concentrations of myo-inositol is found in dietary foods, mainly bran and seeds.[91]

What are inositol’s main benefits?

Inositol shows promise for treating insulin resistance by restoring insulin sensitivity and is commonly used for management of PCOS in women.[92] PCOS is a condition associated with abnormalities in glucose metabolism, including reduced insulin sensitivity and elevated fasting blood glucose.[93] Studies have shown that a potential mechanism for insulin deficiency in PCOS is a deficiency in inositol in inositolphosphoglycan mediators and that administration of D-chiro-inositol could be beneficial.[94] Myo-inositol and its role as a second messenger is believed to improve insulin sensitivity and increase intracellular glucose uptake.[95]

Inositol may also have potential benefits as an anxiolytic. Inositol was initially found to exhibit anxiety-reducing effects in animal studies, and its anxiolytic effects were more notable in the context of stressors perceived as more significant than mild stressors.[96][97] Human studies comparing supplementation with inositol to the SSRI fluvoxamine showed that inositol was as effective in reducing symptoms of anxiety as fluvoxamine.[98]

What are inositol’s main drawbacks?

In general, up to 12 grams of inositol per day is safe to ingest, with some gastrointestinal upset associated with higher doses.[99]

How does inositol work?

Inositols are molecules naturally present in the body that act as second messengers in various cellular processes.[90] In the treatment of PCOS, inositol acts as an insulin sensitizing agent and free radical scavenger, thus improving insulin resistance and ovarian function.[100]

What else is Inositol known as?
Note that Inositol is also known as:
  • Myoinositol
  • Cyclohexanehexol
  • 6-cyclohexanehexol
  • 1 2 3 4 5 6-cyclohexanehexol
Inositol should not be confused with:
  • D-pinitol (structurally related)
Dosage information

For the treatment of polycystic ovarian syndrome (PCOS), myo-inositol is taken in the range of 200-4,000mg once daily before breakfast; the higher dose seems to be used more often and seems more effective.

Neurological usage of inositol tends to require higher doses, and while antidepressant effects have been noted as low as 6g at times the standard dose is between 14-18g daily.

If using a soft gel formulation rather than powdered myo-inositol, then only 30% of the same dose is required to be equivalent. This would mean the 14-18g range for psychopharmacological effects is now reduced to 4.2-5.4g of myo-inositol soft gels.

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