Inositol: benefits, dosage, contraindications
Other name(s)
D-Myo-Inositol, D-chiro-inositol
Scientific name(s)
Hexahydroxycyclohexane
Family or group:
Pseudovitamins
Indications
Scoring methodology
EFSA approval.
Metabolic syndrome ✪✪✪✪✪
Certain clinical research in postmenopausal women with metabolic syndrome who follow a hypocaloric diet shows that taking myo-inositol at a dose of 2 grams twice a day for one year reduces total cholesterol by 29 mg/dL, triglycerides by 64 mg/dL, systolic and diastolic blood pressure by 9 mmHg and 6 mmHg, respectively, increases high-density lipoprotein (HDL) cholesterol by 6 mg/dL and improves insulin resistance compared with placebo. Furthermore, it did not reduce body mass index or waist circumference in these patients. Another clinical study shows that daily intake of a combination of inositol and alpha-lipoic acid for 6 months, in combination with a hypocaloric diet, reduces insulin resistance by at least 20% compared with hypocaloric diet alone. In addition, taking inositol and alpha-lipoic acid appears to increase HDL cholesterol by about 6% and reduce triglycerides by 5% compared with baseline.
Posologie
Oral
4 g
1 - years
Adults
myo-inositol
Synergies
Polycystic ovary syndrome ✪✪✪✪✪
A meta-analysis of clinical research shows that taking inositol modestly reduces fasting blood glucose, fasting insulin, total cholesterol, triglycerides, and testosterone levels compared with control in women with polycystic ovary syndrome. Other clinical studies have shown that taking D-chiro-inositol 1–1.2 grams or myo-inositol 4 grams with 400 mcg folic acid per day for 6 months decreases serum triglyceride and testosterone levels, slightly lowers blood pressure, and improves ovarian function. Other research indicates that taking myo-inositol and D-chiro-inositol together may improve metabolic parameters more quickly than taking myo-inositol alone. A small clinical study shows that taking 4 grams of myo-inositol and 400 mcg folic acid per day for three spontaneous cycles induces ovulation in about 62% of women with anovulatory PCOS and insulin resistance. Another clinical study shows that taking a combination of 2 grams of inositol, 200 mcg folic acid, and 600 mg N-acetylcysteine twice daily for 12 months improves ovulation rates in women with PCOS and oligomenorrhea, regardless of baseline insulin sensitivity.
Posologie
Oral
1 - 4 g
6 months
Women
D-chiro-inositol, myo-inositol
Synergies
Short-term effects of metformin and myo-inositol in women with polycystic ovarian syndrome (PCOS): a meta-analysis of randomized clinical trials
Nutritional supplements and herbal medicines for women with polycystic ovary syndrome; a systematic review and meta-analysis
Ovulatory and metabolic effects of D-chiro-inositol in the polycystic ovary syndrome
Ovulation induction with myo-inositol alone and in combination with clomiphene citrate in polycystic ovarian syndrome patients with insulin resistance
Inositols in Polycystic Ovary Syndrome: An Overview on the Advances
The Efficacy of Inositol and N-Acetyl Cysteine Administration (Ovaric HP) in Improving the Ovarian Function in Infertile Women with PCOS with or without Insulin Resistance
The combined therapy myo-inositol plus D-chiro-inositol, rather than D-chiro-inositol, is able to improve IVF outcomes: results from a randomized controlled trial
Nutritional supplements and herbal medicines for women with polycystic ovary syndrome; a systematic review and meta-analysis
The combined therapy with myo-inositol and D-chiro-inositol reduces the risk of metabolic disease in PCOS overweight patients compared to myo-inositol supplementation alone
Pregnancy ✪✪✪✪✪
A meta-analysis of five clinical trials in women at risk of gestational diabetes shows that daily intake of myo-inositol and folic acid, from the first trimester and throughout pregnancy, reduces the risk of preterm birth by 64% compared with folic acid alone. In most studies, the dose used is 2 grams of myo-inositol plus 200 mcg of folic acid twice a day.
Posologie
Orally
4 g
Pregnant women
myo-inositol
Synergies
Gestational diabetes ✪✪✪✪✪
Most clinical research shows that taking 2 grams of myo-inositol plus 200 mcg of folic acid twice a day from the first trimester and throughout pregnancy decreases the incidence of gestational diabetes by 57% to 92% compared with folic acid alone in patients at risk of gestational diabetes. Myo-inositol appears to be more effective than D-chiro-inositol.
Posologie
By mouth
4 g
Pregnant women
myo-inositol
Synergies
Antenatal dietary supplementation with myo-inositol in women during pregnancy for preventing gestational diabetes
myo-Inositol supplementation and onset of gestational diabetes mellitus in pregnant women with a family history of type 2 diabetes: a prospective, randomized, placebo-controlled study
The efficacy of myo-inositol supplementation to prevent gestational diabetes onset: a meta-analysis of randomized controlled trials
Effect of dietary myo-inositol supplementation in pregnancy on the incidence of maternal gestational diabetes mellitus and fetal outcomes: a randomized controlled trial
Relationship Between Myo-Inositol Supplementary and Gestational Diabetes Mellitus: A Meta-Analysis
Myo-inositol supplementation to prevent gestational diabetes in overweight non-obese women: bioelectrical impedance analysis, metabolic aspects, obstetric and neonatal outcomes - a randomized and open-label, placebo-controlled clinical trial
Obsessive-compulsive disorder ✪✪✪✪✪
A preliminary clinical study in adults with obsessive-compulsive disorder (OCD) shows that taking 18 grams per day of inositol for 6 weeks improves scores on the Yale-Brown Obsessive Compulsive Scale (a scale that provides a measure of the severity of obsessive symptoms) compared with placebo. However, taking inositol does not appear to improve the severity or type of OCD symptoms in patients already taking a selective serotonin reuptake inhibitor. Both studies were small and the treatment was administered for only 6 weeks.
Posologie
Oral
18 g
6 - weeks
Adults
Psoriasis ✪✪✪✪✪
A small clinical study suggests that taking 6 grams per day of inositol for 10 weeks may improve psoriasis associated with lithium therapy.
Posologie
Oral
6 g
10 - weeks
Adults
Properties
Neurological
Inositol is a simple isomer of glucose that is a key metabolic precursor in the phosphatidylinositol (PI) cycle. Unlike L-DOPA and tryptophan, which are amino acid precursors for monoamine neurotransmitters and which may have antidepressant properties, inositol is a precursor of a second intracellular messenger system. The PI cycle is a second messenger system for many neurotransmitters. Decreased brain levels of inositol have been observed in patients suffering from depression, anxiety, and compulsive disorders. In addition, limited clinical evidence suggests that exogenous inositol may have benefits similar to selective serotonin reuptake inhibitors (SSRIs) in conditions such as panic disorder, depression, and obsessive-compulsive disorder.
Usages associés
Metabolic
In vitro and animal studies have shown that insulin resistance is directly linked to a deficiency in D-chiro-inositol and to an imbalance with myo-inositol (two stereoisomers of inositol). D-chiro-inositol acts as a second messenger in insulin signaling and is an insulin sensitizer. In vitro research suggests that it has activity similar to insulin. Inositol is also a precursor of phosphoinositides, which play a role in cell signaling and are also secondary messengers involved in glucose metabolism and have insulin-like effects. In addition, inositol can increase levels of adipocytokines, particularly adiponectin, which are negatively correlated with glucose and insulin concentrations. Finally, myo-inositol can activate lipogenesis via stimulation of acetyl-CoA carboxylase.
Usages associés
Effect on fertility
Clinical research shows that taking myo-inositol, D-chiro-inositol, or the combination of these two forms appears to improve ovulation and pregnancy rates in women with polycystic ovary syndrome.nnClinical research also shows that treating sperm with myo-inositol in vitro increases sperm motility in men with oligoasthenospermia. This increased motility leads to an 18% increase in pregnancy rate during intrauterine insemination compared with controls. nn
Hormonal metabolism
Researchers believe that inositol induces ovulation in women with polycystic ovary syndrome (PCOS) by improving insulin sensitivity. It also produces the second messenger inositol triphosphate, which is involved in the regulation of certain hormones such as thyroid-stimulating hormone and follicle-stimulating hormone. The reduction in insulin resistance is also thought to be responsible for the improvement of other symptoms associated with PCOS, including hypertension, hyperlipidemia, hyperglycemia, obesity, and increased serum testosterone concentrations. nn
Usages associés
Dermatologic effect
Supplemental inositol appears to improve psoriasis that is worsened or triggered by lithium use. The mechanism is unknown, but lithium appears to cause a reduction of inositol both in the brain and in other tissues. Furthermore, inositol supplementation does not appear to reduce the effectiveness of lithium in the treatment of bipolar disorder. nn
Usages associés
Safe dosage
Adults 18 years and older: 1 g - 18 g (D-chiro-inositol, myo-inositol)
Inositol is generally used at doses of 1 to 4 grams per day, often in combination with folic acid 200 to 400 mcg per day. Inositol has been used with apparent safety at doses up to 18 grams per day for 6 weeks or 6 grams per day for 10 weeks.
Pregnant women: 4 g (myo-inositol)
Myo-inositol has been used with apparent safety at doses up to 4 g per day during pregnancy.
Interactions
Médicaments
Antidiabetic: interaction undefined
Clinical research shows that inositol lowers blood glucose and glycated hemoglobin (HbA1c) levels in diabetic patients. Theoretically, taking inositol with antidiabetic medications may increase the risk of hypoglycemia.
Precautions
Type 2 diabetes: use with caution
Clinical research shows that inositol lowers blood glucose and glycated hemoglobin (HbA1c) levels in diabetic patients. Theoretically, taking inositol with antidiabetic medications may increase the risk of hypoglycemia.
Breastfeeding woman: avoid
Breast milk is rich in endogenous inositol. However, the effects of exogenous inositol are not known. Avoid use due to lack of reliable and sufficient information.
