Myo-Inositol Dosage Calculator

What is Myo-Inositol?

Myo-inositol is the most abundant form of inositol, a cyclohexane polyol synthesised endogenously from glucose-6-phosphate (~4 g/day under normal conditions) and obtained from diet (legumes, citrus, nuts). It is the precursor for phosphatidylinositol (PI) — the membrane phospholipid backbone of the PI3K/Akt insulin signalling cascade, FSH receptor downstream signalling, and the phosphoinositide second messenger system that mediates serotonin (5-HT2) receptor activity. Deficiency in inositol metabolism is implicated in three well-characterised conditions: PCOS-related insulin resistance, anxiety/OCD, and gestational diabetes. **PCOS:** The most robust application. In PCOS, inositol phosphoglycan (IPG) mediators — derived from myo-inositol and D-chiro-inositol — are deficient in ovarian granulosa cells, impairing FSH signalling and insulin-mediated glucose disposal. Multiple RCTs confirm that myo-inositol (2 g) + D-chiro-inositol (50 mg) at a 40:1 ratio (matching physiological plasma ratio) restores ovulation in 70% of anovulatory PCOS patients, reduces androgens, improves insulin sensitivity, and lowers fasting glucose — comparably to metformin with superior tolerability. Always discuss PCOS treatment options with your gynaecologist or endocrinologist before beginning supplementation. **Anxiety/OCD:** A 1996 double-blind crossover RCT (Fux et al., American Journal of Psychiatry) found 18 g/day inositol significantly reduced OCD symptom scores; a 1995 trial confirmed anxiety and panic disorder reduction at the same dose.

How to Take Myo-Inositol

**PCOS:** 2,000–4,000 mg myo-inositol + 50–100 mg D-chiro-inositol per day in 2 divided doses, with meals. No formal RDA; no established UL at therapeutic doses. **Anxiety/OCD:** 12–18 g/day inositol powder in divided doses — significantly higher than PCOS doses; begin at 2 g/day and titrate up over 4 weeks. **Gestational diabetes (under obstetric supervision):** 2,000–4,000 mg/day from first trimester. Inositol powder is preferable to capsules at high doses; it is mildly sweet and dissolves easily in water.

Timing Recommendations

Twice-daily dosing with meals for PCOS (morning and evening). For sleep or anxiety, an evening dose 30–60 minutes before bed can support GABAergic tone via serotonin receptor modulation.

Potential Side Effects & Safety

Mild GI effects (nausea, flatulence, loose stools) at doses > 4 g/day, especially when titrated rapidly. At high doses (12–18 g/day for psychiatric indications), GI tolerance is the primary limiting factor. Bipolar disorder caution: inositol may trigger manic episodes in susceptible individuals — consult a psychiatrist before use.

Best Stacks with Myo-Inositol

Myo-inositol (2 g) + D-chiro-inositol (50 mg) at 40:1 for PCOS. Add berberine (500 mg × 3/day) for synergistic insulin sensitisation if metformin is not preferred. Myo-inositol + methylfolate for PCOS patients trying to conceive — addresses both ovulation and neural tube defect prevention simultaneously.

Scientific References

All dosage recommendations are grounded in peer-reviewed research.

1. 1
   Myo-inositol in patients with polycystic ovary syndrome: a novel method for ovulation induction

   Gynecological Endocrinology · 2007

2. 2
   Inositol treatment of obsessive-compulsive disorder

   American Journal of Psychiatry · 1996