Myo-Inositol

A carbocyclic sugar that plays a key role in insulin signaling and hormonal health.

Also known as: Inositol • Vitamin B8 (unofficial)

other Names
Inositol
primary Benefits
Improves insulin sensitivity, supports hormonal balance (especially in PCOS), promotes mood stability
common Dose
2-4 grams per day
best Form
Myo-inositol powder, often combined with D-chiro-inositol in a 40:1 ratio
timing
Can be taken with or without food, often in divided doses
safety Rating
Extremely safe, even at high doses.

Overview

Myo-inositol is a vitamin-like substance, often incorrectly called Vitamin B8. It is a crucial component of cell membranes and a secondary messenger in insulin signaling pathways. It is widely studied for its benefits in improving insulin sensitivity, particularly in conditions like Polycystic Ovary Syndrome (PCOS) and gestational diabetes. It also plays a role in neurotransmitter signaling, affecting mood and mental health.

Key Benefits

Enhances Insulin Signaling

Acts as a secondary messenger, helping cells respond appropriately to insulin, which improves glucose uptake.

Manages PCOS Symptoms

Highly effective for improving insulin resistance, regulating menstrual cycles, and reducing androgen levels in women with PCOS.

Supports Mental Health

Plays a role in the pathways of neurotransmitters like serotonin and dopamine, and has been studied for its benefits in panic disorder, depression, and OCD.

Promotes Metabolic Health

Can help improve triglyceride levels, blood pressure, and overall metabolic syndrome markers.

Dosage & How to Take

Doses are typically in grams, not milligrams.

PurposeDoseNotes
Insulin Resistance/PCOS2-4 g/dayOften taken as 2g in the morning and 2g in the evening. A 40:1 ratio of Myo- to D-chiro-inositol is common.
Mood Support (e.g., Panic Disorder)12-18 g/dayHigh doses are used under clinical supervision.

Best Time to Take

Can be taken anytime. Dividing the dose (e.g., morning and evening) is common for higher amounts.

With or Without Food

Optional. It has a mildly sweet taste and dissolves easily in water.

Forms & Bioavailability

FormAbsorptionBest ForNotes
Myo-InositolHighPrimary form for insulin sensitivity and moodThe most abundant and researched form.
D-Chiro-Inositol (DCI)HighUsed in conjunction with Myo-inositol for PCOSThe body converts Myo-inositol to DCI. Supplementing both in a 40:1 ratio is thought to be optimal for PCOS.

Side Effects & Safety

Common

  • Virtually none at standard doses (2-4g).

Rare

  • At very high doses (12g+), mild gastrointestinal effects like gas, nausea, or diarrhea may occur.

Contraindications

  • None known.

Interactions

None knownNone

Inositol is considered very safe and does not have significant known drug interactions.

Scientific Research

2017Endocrine Connections

Myo-inositol effects in women with PCOS: a meta-analysis of randomized controlled trials

This meta-analysis confirmed that myo-inositol supplementation significantly improves metabolic profiles (improving insulin sensitivity) and restores spontaneous ovulation in women with PCOS.

Food Sources

Abundant in fruits, especially cantaloupe and citrus fruits, as well as beans, grains, and nuts.

Products With Myo-Inositol

2 products in our database contain this ingredient

Frequently Asked Questions

Medical Disclaimer

This content is for educational and informational purposes only and is not intended as medical advice. Always consult with a qualified healthcare professional before starting any supplement regimen, especially if you have pre-existing health conditions or are taking medications. The statements on this page have not been evaluated by the Food and Drug Administration.