Inositol

has been used to help people with anxiety who have panic attacks. Up to 4 grams three times per day was reported to control such attacks in a double-blind trial. Inositol (18 grams per day) has also been shown in a double-blind trial to be effective at relieving the symptoms of obsessive-compulsive disorder.

Preliminary evidence indicates that people with depression may have lower levels of . Supplementation with large amounts of inositol can increase the body’s stores by as much as 70%. In a double-blind trial, depressed people who received 12 grams of inositol per day for four weeks had a significant improvement in symptoms compared to those who took placebo. In a double-blind follow-up to this trial, the antidepressant effects of inositol were replicated. Half of those who responded to inositol supplementation relapsed rapidly when inositol was discontinued.

is a nutrient found in large amounts in the brain, but its possible role in mood disorders is unclear. Inositol levels may be reduced in certain parts of the brains of depressed and bipolar patients. However, lithium reduces normal brain levels of inositol, and this may be one of the ways lithium helps people with bipolar disorder. Although inositol is known to have significant antidepressant properties when administered in large amounts of 12 grams per day, case reports involving bipolar patients have reported either no benefit, some benefit, or worsening of symptoms from inositol supplementation. Until controlled research clarifies the effects of inositol in people with bipolar illness, it should only be used under the supervision of a qualified healthcare practitioner.

Inositol, particularly in the forms myo-inositol and D-chiro-inositol, has many functions in the body, including assisting in normal cellular responsiveness to insulin. A gene alteration that affects inositol metabolism may be associated with risk of type 1 diabetes and its complications, and people with type 1 and type 2 diabetes have been found to lose more myo-inositol in their urine compared to those without diabetes. In one small pilot trial in seven people with type 1 diabetes, inositol supplementation (500 mg taken twice per day for two weeks) led to improved nerve function; however, two placebo-controlled trials failed to find a benefit.

Disturbances in inositol metabolism are thought to be an underlying factor in insulin resistance and type 2 diabetes. Animal studies suggest inositol may reduce glucose absorption in the digestive tract and have insulin-like effects, increasing glucose uptake and utilization by cells. A pilot trial examined the effects of adding inositol in people with type 2 diabetes with persistently high HbA1c despite medical treatment. A supplement providing two types of inositol (550 mg of myo-inositol and 13.8 mg of D-chiro inositol per day) was added to their treatment. After three months, fasting blood glucose levels and HbA1c had decreased significantly. Reviews of clinical research have shown that inositol can improve glucose metabolism and insulin sensitivity in women with polycystic ovarian syndrome (PCOS), a condition marked by hormonal imbalance and increased risk of insulin resistance, type 2 diabetes, and cardiovascular disease.