Our pick · Inositol

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Inositol

A sugar alcohol with good RCT evidence for reducing anxiety and panic symptoms at high doses, with additional data for PCOS — but requires gram-level dosing.

By editorialUpdated 2026-05-251 min read

What it's actually good for

Inositol (specifically myo-inositol) is a sugar alcohol that plays a key role in intracellular signaling, particularly in the phosphatidylinositol second messenger system involved in serotonin and insulin receptor function. For mental health, the most compelling evidence comes from a controlled trial showing that 12-18 g/day of inositol was comparable to fluvoxamine (an SSRI) for panic disorder, with fewer side effects. Additional trials support modest benefits for OCD and general anxiety, though the evidence base is smaller than for conventional pharmaceuticals and some results are inconsistent. A practical challenge is the high dose required: 12-18 grams daily is a tablespoon-plus of powder, which limits compliance. Separately, inositol has a strong and arguably more robust evidence base for polycystic ovary syndrome (PCOS), where myo-inositol at lower doses (2-4 g/day) improves insulin sensitivity and ovulatory function in multiple RCTs. Inositol earns a B because while the controlled trial data for both mood and PCOS is promising and mechanistically sound, the mood/anxiety trials are few in number and relatively small, and the clinical effect sizes, while meaningful, need replication in larger samples.

Claim-by-claim

Each claim graded independently

The overall grade is the floor. Some claims are stronger or weaker than the headline.

B

Reduces symptoms of panic disorder and anxiety

A controlled trial found 12-18 g/day of myo-inositol was as effective as fluvoxamine for panic disorder with fewer side effects. Additional smaller trials support anxiolytic effects, though the evidence base remains limited in size and some results are mixed.

B

May benefit OCD symptoms

A double-blind crossover trial showed 18 g/day of inositol significantly reduced OCD symptoms compared to placebo. However, follow-up studies have been small and results are not fully consistent.

B

Supports metabolic and hormonal health in PCOS

Multiple RCTs show myo-inositol (often combined with D-chiro-inositol in a 40:1 ratio) improves insulin sensitivity, ovulation rates, and hormonal profiles in women with PCOS. This is arguably its most robust evidence base.

Sources

3 cited
[01]METAMyo-inositol and D-chiro-inositol for the treatment of polycystic ovary syndrome: a systematic review and meta-analysisUnfer V, Facchinetti F, Orru B, Giordani B, Nestler J. Gynecol Endocrinol. 2017
[02]RCTDouble-blind, controlled, crossover trial of inositol versus fluvoxamine for the treatment of panic disorderPalatnik A, Frolov K, Fux M, Benjamin J. J Clin Psychopharmacol. 2001
[03]RCTInositol treatment of obsessive-compulsive disorderFux M, Levine J, Aviv A, Belmaker RH. Am J Psychiatry. 1996

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Medical disclaimer. The information on this site is provided for educational purposes only and is not intended as medical advice. It does not constitute a diagnosis, treatment plan, or recommendation for any specific health condition. Always consult a qualified healthcare professional before making changes to your supplement regimen, diet, or lifestyle — especially if you are pregnant, nursing, taking medications, or managing a medical condition.

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