✓ No active regulatory warningsFDA MedWatch, EMA EudraVigilance, WHO VigiBase, WADA Prohibited List · 2026-05-29
⚠ PCOS patient — 4 g/day myo-inositol (40:1 with D-chiro) improves ovulation and metabolic parameters [2]
⚠ GDM prevention — 4 g/day from first trimester in high-risk women [2]
⚠ Panic disorder patient intolerant of SSRIs — 12–18 g/day is a reasonable alternative (single RCT) [1]
⚠ Too much D-chiro-inositol can WORSEN ovarian function — maintain 40:1 ratio [2]
⚠ Lithium depletes inositol — supplementation may reduce lithium efficacy [1]
🥗 Food first — build your daily Typical 2–4 g myo-inositol
Check the foods you regularly eat — the bar fills toward your daily target.
Cantaloupe (100 g)355 mg myo-inositol
Citrus fruit (1 orange)307 mg myo-inositol
Beans (100 g)300 mg myo-inositol
Whole wheat bread (1 slice)100 mg myo-inositol
Brown rice (195 g)80 mg myo-inositol
Check your regular foods above
🔬 Lab interpreter
Recommended test
No routine monitoring for supplement use
No routine monitoring for supplement use
Reference range / target
N/A
Full lab monitoring ↓N/A
⚕ For professionals — confirm ranges against your local laboratory.
Clinical verdict
Inositol has two distinct dose-dependent applications: PCOS at 4 g/day (meta-analysis: improved ovulation, insulin sensitivity, testosterone) and panic/OCD at 12–18 g/day (comparable to fluvoxamine). GDM prevention in pregnancy (4 g/day, first trimester) is one of the best-supported pregnancy supplement interventions. The 40:1 myo:D-chiro ratio matters for PCOS [1] [2].
1 Am I deficient?
Not applicable0%
What happens as status declines
Not applicable
Not an essential nutrient [1].
Risk factors
• Not applicable — not an essential nutrient [1]
🧬 How Inositol works ▼
2 How much do I need?
👤 Adults: Specific dosage data under clinical review
👴 Elderly: Specific dosage data under clinical review
🤰 Pregnancy: See guidance
WELL-STUDIED. 4 g/day reduces GDM incidence in high-risk women (multiple RCTs). Safe. One of the best pregnancy supplement interventions [2].
👦 Pediatric: See guidance
Limited data. Not routinely recommended [1].
🏃 Athletes: Standard dose
⚖️ Obesity: Standard dose
Fat-soluble compounds may require dose adjustment in obesity.
🩺 Renal: Consult specialist
Dose adjustment may be needed in renal impairment.
🌱 Vegan: Standard dose
How to take
🍽 Timing: Divided doses (BID or TID) for high-dose psychiatric use. Once or twice daily for PCOS [1] [2].
💊 With food: With or without food. Sweet taste [1].
🚫 Avoid: Lithium-treated patients without physician guidance [1].
3 Which form?
| Form | Bioavailability | Vegan | Cost |
|---|---|---|---|
| ['Myo-inositol powder', 'preferred', 'Sweet taste, dissolves easily. 4 g/day for PCOS; 12–18 g/day for psychiatric [1].'] | Standard | Check label | |
| ['Myo-inositol + D-chiro-inositol (40:1)', 'preferred for PCOS', 'Physiological ratio. Most PCOS trials use this combination [2].'] | Standard | Check label | |
| ['Inositol capsules', '', '500–1,000 mg per capsule (need many for therapeutic dose) [1].'] | Standard | Check label |
4 Common questions
Can inositol treat anxiety as well as SSRIs? ▼
For panic disorder: one crossover RCT found 12–18 g/day comparable to fluvoxamine with fewer side effects [1]. This is a single trial and insufficient to replace SSRIs for most patients, but it is a reasonable option for SSRI-intolerant patients with panic disorder.
Why is the PCOS dose different from the psychiatric dose? ▼
Is D-chiro-inositol important? ▼
For PCOS: the 40:1 myo:D-chiro ratio mirrors physiological ovarian ratio. Too much D-chiro-inositol may paradoxically worsen ovarian function. The ratio matters [2].
Can inositol prevent gestational diabetes? ▼
Multiple RCTs show myo-inositol 4 g/day started in the first trimester reduces GDM incidence in high-risk women. One of the few evidence-based pregnancy supplement interventions [2].
5 Clinical evidence
Strong
Second messenger in insulin signaling — well-established biochemistry [1]. HIGH
Moderate
PCOS: meta-analysis showed myo-inositol 4 g/day improved ovulation, reduced testosterone, improved insulin sensitivity and metabolic parameters [2]. Panic disorder: 12–18 g/day was comparable to fluvoxamine in a crossover RCT [1]. OCD: some positive trials as SSRI adjunct [1]. Gestational diabetes prevention: myo-inositol 4 g/day reduced GDM incidence in high-risk women in multiple RCTs [2]. MODERATE
Insufficient
6 Safety, toxicity & adverse events
Relative
⚠ Bipolar disorder — may precipitate mania/hypomania
⚠ High doses — gastrointestinal upset
⚠ Pregnancy — myo-inositol is used in pregnancy but should be supervised
🚩 Red flags
● Lithium patient supplementing inositol — may reduce lithium efficacy [1]
● PCOS patient taking pure D-chiro-inositol (not 40:1 ratio) — may worsen ovarian function [2]
7 Interactions
Drug interactions
Lithium Moderate
Mechanism: Lithium depletes inositol (inhibits inositol monophosphatase — its therapeutic mechanism). Exogenous inositol may counteract this. [1]
Effect: Potentially reduced lithium efficacy. [1]
Action: Discuss with psychiatrist before supplementing [1].
Supplement synergies
D-Chiro-Inositol (40:1 ratio) · 110 µg D-chiro per 4 g myo-inositol
Physiological ovarian ratio. The most effective PCOS formulation [2].
Physiological ovarian ratio. The most effective PCOS formulation [2].
Folate · 400 µg folate
Common PCOS co-formulation. Supports fertility [2].
Common PCOS co-formulation. Supports fertility [2].
8 Laboratory monitoring
No routine monitoring for supplement use Primary
Target: N/A · N/A [1].
9 Regulatory
United States (FDA): GRAS. Dietary supplement [1].
European Union: Food supplement. Widely used for PCOS in Europe [2].
Italy: Particularly popular for PCOS (major research center for inositol in PCOS) [2].
South Korea: Dietary supplement.
10 US supplement products
954
on-market products containing Inositol (NIH DSLD)
Brands carrying Inositol (261)
Click a brand to see its Inositol products.
11 Frequently paired with
12 References (2)
[1]National Institutes of Health, MedlinePlus. Inositol. Updated 2024. medlineplus.gov REVIEW Accessed: 2026-05-29
[2]Unfer V, et al. Myo-inositol effects in women with PCOS: a meta-analysis of randomized controlled trials. Endocr Connect. 2017;6(8):647-658. doi:10.1530/EC-17-0243 META-ANALYSIS Accessed: 2026-05-29
13 Related articles
Auto-populated from GMJ Newsroom. Articles tagged "Inositol".
14 Cite this page
Vancouver: Pkhakadze G. Inositol — safety profile [Internet]. Tbilisi: PHIG; 2026 [cited 2026 Jun 02]. Available from: https://supplement.ge/ingredients/inositol/
APA 7th: Pkhakadze, G. (2026). Inositol — Safety profile. Public Health Institute of Georgia. https://supplement.ge/ingredients/inositol/
📋 Editorial information
Author: Prof. G. Pkhakadze, MD, MPH, PhD
Institution: Public Health Institute of Georgia (PHIG)
Affiliation: David Tvildiani Medical University (DTMU)
First published: January 2026
Last reviewed: 2026-05-29
Next review: December 2026
References: 2 cited sources
COI: SupplementIndex receives no funding from supplement manufacturers. All content independently authored by PHIG.
Process: Systematic literature review
📄 License & reuse
Published under Creative Commons Attribution 4.0 International (CC BY 4.0). You may share and adapt for any purpose with attribution.
Pkhakadze G. "Inositol — Safety Profile." SupplementIndex, PHIG, 2026. https://supplement.ge/ingredients/inositol/ CC BY 4.0.
GP
Educational and public health purposes. CC BY 4.0. Consult your healthcare provider before starting any supplement. Corrections: info@accreditation.ge. Publisher: PHIG