Myoinositol for PCOS: Benefits, Contraindications, Side Effects, and Discontinuation
Myoinositol is an effective supplement for PCOS that improves insulin sensitivity, reduces hyperandrogenism, and restores ovulation in approximately 70% of women, with minimal side effects and good safety profile. 1, 2
Benefits of Myoinositol in PCOS
- Myoinositol improves insulin sensitivity, reducing insulin levels and subsequently decreasing ovarian androgen production in women with PCOS 1, 3
- Approximately 70% of women with PCOS experience restored ovulation with myoinositol treatment 2, 3
- Myoinositol treatment can lead to significant reductions in testosterone levels (from 96.6 ng/mL to 43.3 ng/mL) and increases in progesterone levels (from 2.1 ng/mL to 12.3 ng/mL) after 12 weeks of treatment 2
- Pregnancy rates of approximately 15% have been reported with myoinositol treatment in women with PCOS 2
- The combination of myoinositol and D-chiro-inositol in a physiological ratio (40:1) provides better clinical results, including reduction of insulin resistance, androgen levels, cardiovascular risk, and regularization of menstrual cycles 1
- Myoinositol improves oocyte and embryo quality in women with PCOS undergoing assisted reproductive technologies 4, 5
Contraindications and Precautions
While current guidelines from ACOG and other major organizations do not specifically address myoinositol for PCOS treatment 6, 7, based on available research:
- No specific contraindications have been documented in the literature for myoinositol use in PCOS 4, 2
- Caution should be exercised when using myoinositol concurrently with other insulin-sensitizing agents like metformin, as there could be additive effects on insulin sensitivity 1
- Women who are pregnant or breastfeeding should consult with their healthcare provider before using myoinositol, as safety data in these populations is limited 4
Side Effects
- Myoinositol has a favorable safety profile with no moderate to severe side effects reported at dosages of 4000 mg per day 4, 2
- Mild gastrointestinal symptoms such as nausea, diarrhea, or mild abdominal discomfort may occur but are generally well-tolerated 2
- Long-term safety data beyond 12 weeks of treatment is limited but no significant concerns have been reported in the available literature 2, 3
When to Discontinue Myoinositol
- Discontinue if pregnancy is achieved, unless specifically recommended by a healthcare provider to continue during pregnancy 4, 2
- Consider discontinuation if no improvement in symptoms or laboratory parameters is observed after 3-6 months of treatment 3
- If significant side effects occur, though these are rare with myoinositol treatment 4, 2
- Reassess the need for continued treatment periodically, especially if other treatments for PCOS are initiated 1
Comparison with Standard PCOS Treatments
- Current guidelines from ACOG recommend combined oral contraceptives as first-line pharmacological treatment for PCOS in women not attempting to conceive 6, 7
- For women attempting to conceive, ACOG recommends clomiphene citrate as first-line treatment 6
- Metformin is recommended for women with PCOS who have cardiometabolic features such as abdominal obesity and insulin resistance 8
- Myoinositol has shown pregnancy rates at least equivalent to or potentially superior to those reported with metformin use 2
- Weight loss of even 5% of initial weight significantly improves both metabolic and reproductive abnormalities in PCOS and should be recommended alongside any pharmacological treatment 6, 7
Dosage and Administration
- The most commonly studied effective dosage is 2000 mg myoinositol twice daily (4000 mg total) plus 200 μg folic acid twice daily 4, 2
- Treatment duration of at least 12 weeks is typically needed to observe significant improvements in hormonal parameters 2, 3
- Some studies suggest combining myoinositol with D-chiro-inositol in a 40:1 ratio for optimal results 1