Clinical research has shown the following effects of inositol supplementation:

  • restores normal ovulatory activity
  • increases fertilization rate
  • prevents spina bifida birth defect
  • lowers free testosterone (research has shown up to a 73% reduction)
  • lowers total testosterone (as much as 65% reduction)
  • lowers LH (as much as 55% reduction)
  • lowers insulin response after meals (as much as 62% reduction)
  • lowers DHEA-S (as much as 49% reduction)
  • increases SHBG (as much as 92% increase)
  • lowers androstenedione (as much as 27% reduction)
  • lowers triglycerides (as much as 51% reduction)
  • lowers blood pressure (minor decrease)
  • increases peak progesterone (129% increase in one study)

Inositol and Miscarriage

Myo-inositol reduces the negative effects of hyperglycemia on embryonic growth

To demonstrate the myo-inositol depletion hypothesis in hyperglycemia-induced embryopathy, rat conceptuses of 9.5 days of gestation in the early head-fold stage were grown in vitro during neural tube formation for 48 h with increasing amounts of glucose. Supplementation of the myo-inositol completely restored the myo-inositol content of the embryos and resulted in a significant decrease in the frequency of neural lesions (7.1% vs 23.9%) and a significant increase in crown-rump length and somite numbers. Much less significantly, sorbitol accumulation was also observed in the extra-embryonic membrane in response to hyperglycemia, neither hyperglycemia nor the myo-inositol supplementation modified the myo-inositol contents of the extra-embryonic membrane.

Inositol and Fertility

Myo-inositol restores normal ovulatory activity and fertility in women with PCOS

Myo-inositol combined with folic acid (Inofolic) 4 g a day was administered continuously for 6 months. RESULTS: Twenty-two out of the 25 (88%) patients restored at least one spontaneous menstrual cycle during treatment, of whom 18 (72%) maintained normal ovulatory activity during the follow-up period. A total of 10 singleton pregnancies (40% of patients) were obtained. Nine clinical pregnancies were assessed with fetal heart beat at ultrasound scan. Two pregnancies evolved in miscarriage. CONCLUSION: Myo-inositol is a simple and safe treatment that is capable of restoring spontaneous ovarian activity and consequently fertility in most patients with PCOS.

4 g/day myo-inositol improves egg quality and pregnancy rate in women with failed IVF

Recently, a number of studies have shown that the presence of several compounds in the follicular fluid positively correlates with oocyte quality and maturation (i.e., myo-inositol and melatonin). In the present study, we aim to evaluate the pregnancy outcomes after the administration of myo-inositol combined with melatonin in women who failed to conceive in previous in vitro fertilization (IVF) cycles due to poor oocyte quality. Materials and methods. Forty-six women were treated with 4 g/day myo-inositol and 3 mg/day melatonin (inofolic® and inofolic® Plus) for 3 months and then underwent a new IVF cycle. Results. After treatment, the number of mature oocytes, the fertilization rate, the number of both, total and top-quality embryos transferred were statistically higher compared to the previous IVF cycle, while there was no difference in the number of retrieved oocyte. After treatment, a total of 13 pregnancies occurred, 9 of them were confirmed echographically; four evolved in miscarriage. Conclusion. The treatment with myo-inositol and melatonin improves ovarian stimulation protocols and pregnancy outcomes in infertile women with poor oocyte quality.

Inositol improved pregnancy rate and lowered cancellation rate in PCOS infertility patients

In an attempt to evaluate the role of inositol supplementation in insulin-resistant patients with polycystic ovary syndrome (PCOS), undergoing gonadotropin ovulation induction using the low-dose step-down regimen, we conducted a prospective longitudinal study comparing the stimulation characteristics of 15 patients treated with inositol, to a cohort, matched by age and body mass index (BMI), without inositol. Inositol nutritional supplementation produced very good clinical results with a significant reduction in cancellation rate (0 vs. 40%) and the consequent improvement in clinical pregnancy rate (33.3% vs. 13.3%).

D-chiro-inositol reduces spina bifida birth defect by 86%

Although D-chiro- and myo-inositol both reduced the frequency of spina bifida in curly tail mice by all routes of administration, D-chiro-inositol consistently exhibited the more potent effect, reducing spina bifida by 73–86% in utero compared with a 53–56% reduction with myo-inositol. Pathological analysis revealed no association of either myo- or D-chiro-inositol with reduced litter size or fetal malformation. CONCLUSIONS: D-chiro-inositol offers a safe and effective method for preventing folic acid-resistant neural tube defects in the curly tail mouse. This raises the possibility of using inositol as an adjunct therapy to folic acid for prevention of neural tube defects in humans.

Comparison of D-Chiro-Inositol vs. Myo-Inositol

Overall, the effects of D-chiro-inositol vs. myo-inositol are nearly identical, except that D-chiro-inositol may be effective at lower dosages. The table below compares two recent studies:


D-chiro-inositol lowers free testosterone by 55% and resumes ovulation in 86% of PCOS women

In the 22 obese women with PCOS given 1200 mg/day of d-chiro-inositol for 6 to 8 weeks, the mean area under the plasma insulin curve after the oral administration of glucose decreased from 13,417 to 5158 µU/ml/min; glucose tolerance did not change significantly. The serum free testosterone concentration in these 22 women decreased from 1.1 to 0.5 ng/dL. The women's diastolic and systolic blood pressure decreased by 4 mm Hg, and their plasma triglyceride concentrations decreased from 184 to 110 mg per deciliter (2.1 to 1.2 mmol per liter). None of these variables changed appreciably in the placebo group. Nineteen of the 22 women who received d-chiro-inositol ovulated, as compared with 6 of the 22 women in the placebo group. Conclusions: d-Chiro-inositol increases the action of insulin in patients with PCOS, thereby improving ovulatory function and decreasing serum testosterone concentrations, blood pressure, and plasma triglyceride concentrations.

D-chiro-inositol improves insulin sensitivity by 36% and lowers free testosterone by 73%

In the 10 women given D-chiro-inositol (600 mg/day for 6 to 8 weeks), the mean area under the plasma insulin curve after oral administration of glucose decreased significantly from 8,343 mU/mL/min to 5,335 mU/mL/min. Concomitantly, the serum free testosterone concentration decreased significantly from 0.83 ng/dL to 0.22 ng/dL. Six of the 10 women (60%) in the D-chiro- inositol group ovulated in comparison with 2 of the 10 women (20%) in the placebo group. Systolic and diastolic blood pressures, as well as plasma triglyceride concentrations, decreased significantly in the D-chiro- inositol group . We conclude that, in lean women with PCOS, D-chiro-inositol reduces circulating insulin, decreases serum testosterone, and ameliorates some of the metabolic abnormalities (increased blood pressure and hypertriglyceridemia) of syndrome X.

D-chiro-inositol levels are lower in women with PCOS

Urinary clearance of D-chiro-inositol is inversely correlated with insulin sensitivity in women and is a strong independent predictor of insulin resistance in multivariate models. The urinary clearance of D-chiro-inositol was increased almost sixfold in PCOS compared with normal women, but not myo-inositol clearance. PCOS, which is characterized by insulin resistance, is associated with a selective increase in urinary clearance of D-chiro-inositol and impaired D-chiro-inositol containing-IPG release in response to insulin. These findings are consistent with a defect in tissue availability or utilization of D-chiro-inositol in PCOS that may contribute to the insulin resistance of the syndrome.


Myo-inositol lowers testosterone, increases SHBG and progesterone, and improves insulin sensitivity

In 23 women treated with Myo-inositol (4g for 12 to 16 weeks), the area under the plasma insulin curve after oral administration of glucose decreased from 8.54 to 5.535 μU/ml/min. The serum total testosterone decreased from 99.5 to 34.8 ng/dl, and serum free testosterone from 0.85 to 0.24 ng/dl. SHBG increased from 144 to 198. The progesterone peak value was higher in the Myo-inositol group (15.1 ng/ml). Plasma triglycerides decreased from 195 to 95 mg/dl. Systolic blood pressure decreased from 131 to 127 mmHg. Diastolic blood pressure decreased from 88 to 82 mmHg. The index of composite whole body insulin sensitivity increased from 2.80 to 5.05 mg-2/dl-2 . Also, 16 out of 23 women of Myo-inositol group ovulated (4 out of 19 in placebo group).

Myo-inositol lowers LH, testosterone, and insulin resisitance

After 3 months of myo-inositol administration, plasma LH, testosterone, free testosterone, insulin and HOMA index resulted significantly reduced; no significant changes were observed in plasma FSH and androstenedione levels.

Myo-inositol begins working within one week, restores ovulation, induces weight loss

Of the 92 patients randomized, 47 received 400 mcg folic acid as placebo, and 45 received myo-inositol plus folic acid (4 g myo-inositol plus 400 mcg folic acid). The ovulation frequency assessed by the ratio of luteal phase weeks to observation weeks was significantly higher in the treated group (25%) compared with the placebo (15%), and the time to first ovulation was significantly shorter [24.5 d compared with 40.5 d]. The number of patients failing to ovulate during the placebo-treatment period was higher in the placebo group, and the majority of ovulations were characterized by normal progesterone concentrations in both groups. The effect of myo-inositol on follicular maturation was rapid, because the estrogen circulating concentration increased over the first week of treatment only in the myo-inositol group. A significant increase in circulating high-density lipoprotein was observed only in the myo-inositol-treated group. Metabolic risk factor benefits of myo-inositol treatment were not observed in the morbidly obese subgroup of patients. After 14-wk myo-inositol or placebo therapy, no change in fasting glucose concentrations, fasting insulin, or insulin responses to glucose challenge was recorded. There was an inverse relationship between body mass and treatment efficacy. In fact, a significant weight loss (and leptin reduction) was recorded in the myo-inositol group, whereas the placebo group actually increased weight. These data support a beneficial effect of myo-inositol in women with oligomenorrhea and PCOS in improving ovarian function.

Myo-inositol lowers testosterone, FSH, LH, cholesterol, and insulin resistance

Forty-six hirsute women were enrolled and evaluated at baseline and after receiving myo-inositol therapy for 6 months. No changes in BMI were observed. The hirsutism decreased after therapy. Total testosterone, FSH and LH concentrations decreased while estrogen concentrations increased. There was a slight non-significant decrease in total cholesterol concentrations, an increase in HDL cholesterol concentrations and a decrease in LDL cholesterol concentrations. No significant changes were observed in serum triglyceride, apolipoprotein B and lipoprotein(a) concentrations. Insulin resistance, analysed by homeostasis model assessment, was reduced significantly after therapy. Administration of oral myo-inositol significantly reduced hirsutism and hyperandrogenism and ameliorated the abnormal metabolic profile of women with hirsutism.

Inositol and Insulin Resistance

High insulin associated with low inositol, regardless of PCOS or obesity

Women with or without PCOS, display increased urinary clearance of D-chiro-inositol and decreased area under the curve of D-chiro-inositol-containing inositolphosphoglycan in association with higher insulin levels but independent of adiposity. Increased clearance of inositols might reduce tissue availability of D-chiro-inositol and decrease the release of D-chiro-inositol-containing inositolphosphoglycan mediator, which could contribute to insulin resistance and compensatory hyperinsulinemia.

Inositol is necessary for insulin effectiveness

Evidence suggests that some actions of insulin are effected by inositolphosphoglycan mediators. We hypothesize that a deficiency in D-chiro-inositol and/or a D-chiro-inositol-containing inositolphosphoglycan may contribute to insulin resistance in humans. The urinary clearance of D-Chiro-Inositol was increased almost sixfold in PCOS compared with normal women, but not myo-inositol clearance. Urinary clearance of D-Chiro-Inositol correlated inversely with insulin sensitivity when all women were analyzed together and was one of the three best independent parameters predicting insulin sensitivity. These findings are consistent with a defect in tissue availability or utilization of D-chiro-inositol in PCOS that may contribute to the insulin resistance of the syndrome.

Inositol Information

Inositol is required for many important processes in the body

Inositol and a number of its mono and polyphosphates function as the basis for a number of signaling and secondary messenger molecules. They are involved in a number of biological processes, including: insulin signal transduction, cytoskeleton assembly, nerve guidance, intracellular calcium concentration control, cell membrane potential maintenance, serotonin activity modulation, breakdown of fats and reducing blood cholesterol, gene expression.

Myo-inositol was once considered a vitamin and is produced by the body

Myo-Inositol was once classified as a member of the vitamin B complex. However, because it is produced by the human body from glucose, it is not an essential nutrient. Some substances such as niacin can also be synthesized in the body, but are not made in amounts considered adequate for good health, and thus are still classified as essential nutrients. However, there is no convincing evidence that this is the case for Myo-inositol.

Inositol is found in many healthy foods

Inositol or its phosphates and associated lipids are found in many foods, in particular, in cereals with high bran content, nuts, beans, and fruit, especially cantaloupe melons and oranges.

High doses of inositol may induce labor

Researchers have documented the preventive effect of inositol in folate-resistant neural tube defects in rats and mice, as well as its positive effect in treating hyperglycemia-induced embryopathy. However, inositol may cause dose-related uterine contractions because it has an intimate relationship with oxytocin, a key uterine stimulator. Oxytocin activates phospholipase C to produce inositol-1,4,5-triphosphate, which causes the release of calcium from intracellular stores and stimulates uterine contractions. Thus, it is possible that inositol in high doses may stimulate uterine contractions via its role in the oxytocin stimulatory pathway, making it potentially dangerous for pregnant women.;col1


According to a popular website for purchasing buckwheat farinetta, 1/2 cup of buckwheat farinetta flour has roughly 600 mg of D-chiro-inositol. So, if one bakes 12 muffins using 3 cups of buckwheat farinetta flour, then one can get 600 mg of D-chiro-inositol every day by eating 2 muffins. D-chiro-inositol is also available in pill form without a prescription online, but is difficult (or impossible) to find locally. Myo-inositol is available over the counter at most health food stores, often combined with choline.

Other topics covered under Inositol:

Other topics covered under Supplements and Miscarriage: