Myo-Inositol: Practical Guide for PCOS, Fertility & Metabolic Health
Myo-inositol is a vitamin-like molecule your body uses to help cells respond to insulin, regulate hormones, and support egg quality. It's one of the most commonly used supplements for women with PCOS, and research also looks promising for insulin resistance, fertility support, and even mood. If you're considering myo-inositol, here’s what actually matters: how it works, how much to take, what to expect, and safety tips you can use today.
How myo-inositol helps
For PCOS, myo-inositol improves insulin signaling and can lower insulin and androgen levels. That often leads to more regular cycles and better ovulation. In fertility, studies show improved oocyte quality and higher chances of successful IVF when women take myo-inositol for several months beforehand. For metabolic health, myo-inositol can reduce fasting insulin and improve markers of insulin resistance. Some people also report better mood and reduced anxiety when insulin and hormonal balance improve.
How to dose and use it
The most common and studied dose is 2 grams of myo-inositol taken twice daily (total 4 g/day). Many clinical trials combine 2 g myo-inositol + 200 mcg folic acid twice daily for PCOS and fertility. There's also a popular combination using myo-inositol and D-chiro-inositol in a 40:1 ratio—this mimics the natural balance in the body and may help some women more than myo-inositol alone. If you’re trying to prevent gestational diabetes, trials often use 2 g twice daily, but always check with your obstetrician first.
Start with the recommended dose on the product label or the dose your clinician suggests. Expect to wait at least 2–3 months to see changes in menstrual cycle or ovulation; metabolic changes can show up earlier, within weeks.
Safety, side effects, and interactions
Myo-inositol is generally safe. Side effects are usually mild and digestive—bloating, nausea, or diarrhea—so take it with food if that happens. It can lower blood sugar, so talk to your doctor if you use diabetes medications; dose adjustments may be needed. If you’re pregnant, breastfeeding, or have chronic kidney disease, get medical advice before starting any new supplement. Check with your clinician before combining myo-inositol with other hormone or fertility treatments.
When choosing a product, look for clear labeling of myo-inositol amount, third-party testing, and minimal fillers. Powders are cost-effective and easy to split into doses; capsules can be more convenient for travel. Track your cycle, fasting insulin, or A1c depending on your goals, and give a supplement a fair trial of 3 months before judging results.
If you want specific advice for PCOS, fertility plans, or drug interactions, talk to your healthcare provider. For quick reads on related topics—PCOS dosing, myo- vs D-chiro-inositol, and supplements that pair well—check related guides on GlobalCareRx.
