Myo-inositol is a naturally occurring sugar alcohol, one of the stereoisomers of inositol, which plays a crucial role in cell signaling, insulin sensitivity, and hormone balance. It is widely used as a supplement, particularly for conditions like polycystic ovary syndrome (PCOS), metabolic syndrome, and insulin resistance. Myo-inositol functions intracellularly as a second messenger affecting hormones such as insulin and follicle-stimulating hormone (FSH), and helps regulate glucose uptake and metabolism.
Benefits of Myo-Inositol
- Improves metabolic parameters in PCOS, including reducing fasting insulin and improving insulin resistance (HOMA index), potentially lowering testosterone levels and increasing sex hormone-binding globulin (SHBG) in women with PCOS.
- Enhances insulin sensitivity and glucose utilization by promoting glucose transporter activity and glycogen synthesis.
- May reduce the risk of preterm birth when taken with folic acid during pregnancy.
- Some evidence supports benefits for mental health conditions, though this is less established.
Usage and Dosage
- For PCOS: typically 2 grams twice daily, sometimes combined with d-chiro-inositol or folic acid, for several months.
- For metabolic syndrome: similar dosing over a longer period.
- For mental health conditions: higher doses (12–18 grams daily) for short periods have been studied.
Safety and Side Effects
- Generally safe for most adults when taken orally, with mild side effects such as diarrhea, nausea, and gas.
- Not recommended for women with low androgen levels or certain infertility conditions since it can lower testosterone further, potentially affecting ovarian function and egg quality.
- Interaction with diabetes medications requires careful blood sugar monitoring due to potential additive blood sugar-lowering effects.
Myo-inositol is distinguished from other forms of inositol by its role in hormone regulation, especially in female reproductive health, and is one of the primary forms found in supplements designed for PCOS and insulin-related conditions.
