Recommended Dose of Myo-Inositol for PCOS

The recommended dose of myo-inositol for PCOS is 4000 mg per day (2000 mg twice daily), typically combined with 400 μg folic acid daily.

Standard Dosing Protocol

Administer 2000 mg myo-inositol twice daily (total 4000 mg/day) combined with 200 μg folic acid twice daily (total 400 μg/day) 1, 2
This dosing regimen has been validated in large clinical studies with 3602 patients and demonstrates safety with good compliance 1
Treatment duration should be at least 2-3 months before assessing clinical response, with optimal effects seen at 6 months 1, 3

Lower dose option: 1000 mg twice daily (2000 mg/day total) can be used and has shown efficacy in restoring menstrual regularity and improving hormonal parameters 3
This lower dose may be appropriate for patients with milder metabolic dysfunction or those concerned about cost

The 4000 mg/day regimen demonstrates:

70% restoration of ovulation in treated women 1
15.1% pregnancy rate among all users 1
Significant reduction in testosterone levels (from 96.6 ng/mL to 43.3 ng/mL) and increase in progesterone (from 2.1 ng/mL to 12.3 ng/mL) after 12 weeks 1
88% of patients restore at least one spontaneous menstrual cycle, with 72% maintaining normal ovulatory activity 4

The 2000 mg/day regimen shows:

Initiate therapy for minimum 3 months before considering ovulation induction agents 2
For fertility outcomes, continue for 6 months to assess full reproductive benefit 1, 3
Monitor menstrual regularity, hormonal parameters (LH, testosterone, insulin), and metabolic markers (HOMA-IR) at 3-month intervals 3

Myo-inositol 4000 mg/day can be used as monotherapy without metformin, showing comparable clinical pregnancy rates (45.5% vs 42.0%) 2
When combined with metformin (1500 mg/day), no additional benefit in pregnancy rates is observed, but gastrointestinal side effects increase significantly 2
Myo-inositol monotherapy is preferred over combination with metformin due to equivalent efficacy with better tolerability 2

Obese PCOS patients with hyperinsulinemia (fasting insulin >12 μU/ml):

Use standard 4000 mg/day dose 5
These patients show more pronounced improvement in insulin sensitivity compared to those with normal fasting insulin 5
Expect significant decrease in fasting insulin (from 20.3 to 12.9 μU/ml) and insulin AUC under OGTT 5

IVF protocols:

Administer 4000 mg/day for 2 months prior to starting IVF 1
This improves oocyte quality, follicle-to-oocyte ratio, fertilization rates, and embryo quality 1
Reduces FSH units needed and duration of stimulation 1

No moderate to severe side effects reported at 4000 mg/day dosing 1
Significantly fewer gastrointestinal side effects compared to metformin-containing regimens 2
Safe for use in pregnancy planning and does not increase multiple pregnancy risk 4

While myo-inositol is not mentioned in older ACOG guidelines 6, emerging evidence supports its role as an insulin-sensitizing agent 6:

Initiate lifestyle modification (5% weight loss target) concurrently with myo-inositol therapy 7
Myo-inositol can be used before or instead of metformin for insulin sensitization 2
For women not attempting conception, oral contraceptives can be combined with myo-inositol 7
Reserve clomiphene citrate for patients who fail to conceive after 3-6 months of myo-inositol therapy 1

Do not use doses below 2000 mg/day as efficacy data is limited for lower doses 1, 3, 4
Do not discontinue therapy before 3 months as hormonal and metabolic improvements require this minimum duration 1, 3
Do not automatically add metformin to myo-inositol as monotherapy is equally effective with better tolerability 2
Do not forget folic acid supplementation (400 μg/day) which is consistently combined with myo-inositol in successful protocols 1, 2, 4