Also known as Myo-inositol, D-Chiro-inositol
Sugar alcohol, not a true vitamin, involved in insulin signal transduction and cell membrane structure; myo-inositol is well studied for improving insulin sensitivity and ovulation in PCOS, and for reducing panic and anxiety symptoms.
Reported side effects:Gastrointestinal upset — a 2014 meta-analysis of psychiatric randomised trials (pooled doses in the 12-18 g/day range) reported marginally more gastrointestinal upset with inositol than placebo (p=0.06); no increase in discontinuationsMinimal side effects reported in a 12 g/day panic-disorder crossover trial (21 adults)
Be careful if: pregnant, breastfeeding
Suspect a side effect? Report it to the MHRA Yellow Card scheme ↗
We link to relevant studies and leave interpretation to you and your healthcare professional.
The large figures are what the studies reported for each thing they measured. Open a card for every result.
Colour keyReported a benefitNo clear benefitUnclearPossible harmAmber is for highlights, such as where the most research is. It never means a result was good.
Also measured alongside: Depression symptoms (no clear benefit).
Every resultNo figure given: Panic attack frequency and severity (reported a benefit); Panic attacks and agoraphobia (reported a benefit).
Also measured alongside: ADHD symptoms (possible harm); Agoraphobia severity (reported a benefit); Alzheimer's symptoms (no clear benefit); and 5 more.
Every resultNo figure given: Hormone levels (reported a benefit); Menstrual cycle regularity (reported a benefit).
Also measured alongside: Insulin resistance (reported a benefit); Metabolic markers (reported a benefit).
Every resultWhat sources report about side effects, who should be careful, and medicines to ask about first.
| Reported effect | How often | Basis | Sources |
|---|---|---|---|
| Gastrointestinal upset — a 2014 meta-analysis of psychiatric randomised trials (pooled doses in the 12-18 g/day range) reported marginally more gastrointestinal upset with inositol than placebo (p=0.06); no increase in discontinuations | unknown | Listed by PubMed corpus rows (PubMed 24424706) | Mukai T, Kishi T, Matsuda Y, Iwata N. A meta-analysis of inositol for depression and anxiety disorders. Hum Psychopharmacol 2014;29(1):55-63 (PMID 24424706) |
| Minimal side effects reported in a 12 g/day panic-disorder crossover trial (21 adults) | unknown | Listed by PubMed corpus rows (PubMed 7793450) | Benjamin J, Levine J, Fux M, Aviv A, Levy D, Belmaker RH. Double-blind, placebo-controlled, crossover trial of inositol treatment for panic disorder. Am J Psychiatry 1995;152(7):1084-6 (PMID 7793450) |
| Applies to | What sources say | Sources |
|---|---|---|
| pregnant | In randomised-trial data pooled for overweight and obese pregnant women, inositol supplementation was associated with fewer preterm births (RR 0.28) and less pre-eclampsia (RR 0.40) than placebo, and a 2026 pregnancy review reports a favourable maternal and fetal profile in the available data; no harm signal was located in the sources checked. A legacy note claiming uterine contractions could not be confirmed and is flagged for review. | Chen Z, Xiao G, Liu H, Zuo L, Ye J, Liu G. Effects of Nutritional Supplement Intake on Pregnancy Outcomes in Overweight and Obese Women: A Systematic Review and Meta-Analysis. J Obstet Gynaecol Res 2026;52(3):e70244 (PMID 41871887)Baboun D, et al. Myo-Inositol in Pregnancy: Implications for Acne Management. J Drugs Dermatol 2026;25(7):611-614 (PMID 42406354) |
| breastfeeding | No breastfeeding-specific data located in the sources checked; safety while breastfeeding is not established. | Baboun D, et al. Myo-Inositol in Pregnancy: Implications for Acne Management. J Drugs Dermatol 2026;25(7):611-614 (PMID 42406354) |
Mukai T, Kishi T, Matsuda Y, Iwata N. A meta-analysis of inositol for depression and anxiety disorders. Hum Psychopharmacol 2014;29(1):55-63 (PMID 24424706)Benjamin J, Levine J, Fux M, Aviv A, Levy D, Belmaker RH. Double-blind, placebo-controlled, crossover trial of inositol treatment for panic disorder. Am J Psychiatry 1995;152(7):1084-6 (PMID 7793450)Chen Z, Xiao G, Liu H, Zuo L, Ye J, Liu G. Effects of Nutritional Supplement Intake on Pregnancy Outcomes in Overweight and Obese Women: A Systematic Review and Meta-Analysis. J Obstet Gynaecol Res 2026;52(3):e70244 (PMID 41871887)Baboun D, et al. Myo-Inositol in Pregnancy: Implications for Acne Management. J Drugs Dermatol 2026;25(7):611-614 (PMID 42406354)
Audited published research for Inositol by condition. Drill into a pair page for the full breakdown.
What this means: Bars count reported findings, not treatment effectiveness or certainty.
One study may report several findings or appear in more than one pairing. Counts do not show the size of an effect. Comparable numerical estimates are not established for this summary.
| Compound and condition | Findings (count) | Studies (count) | Reported results (finding counts) | How sure? |
|---|---|---|---|---|
| Anxiety | 3 | 1 | Benefit: 0; no benefit: 3; harm: 0; unclear: 0; not recorded / unrecognised: 0 | Not formally graded |
| Panic Attacks | 12 | 3 | Benefit: 7; no benefit: 4; harm: 1; unclear: 0; not recorded / unrecognised: 0 | Not formally graded |
| PCOS | 5 | 1 | Benefit: 5; no benefit: 0; harm: 0; unclear: 0; not recorded / unrecognised: 0 | Not formally graded |
Where people report using it and what trials suggest
Common claims the trials do not support
Myo-inositol has the strongest PCOS evidence of any supplement in this set — insulin sensitivity and ovulation restoration at proper doses.
Evidence grades reflect study quality and consistency, not marketing claims.
Ordered by strength of evidence, then result direction.
01Comparison of metformin with inositol versus metformin alone in women with polycystic ovary syndrome: a systematic review and meta-analysis of randomized controlled trialsKelly FA, et al. · Endocrine · 2025PMID 39331347 ↗02Transdiagnostic reduction in cortical choline-containing compounds in anxiety disorders: a (1)H-magnetic resonance spectroscopy meta-analysisMaddock RJ, et al. · Molecular psychiatry · 2025PMID 40913113 ↗03Inositol for Polycystic Ovary Syndrome: A Systematic Review and Meta-analysis to Inform the 2023 Update of the International Evidence-based PCOS GuidelinesFitz V, et al. · The Journal of clinical endocrinology and metabolism · 2024PMID 38163998 ↗04Nutrition and bipolar disorder: a systematic reviewGabriel FC, et al. · Nutritional neuroscience · 2023PMID 35608150 ↗05Polycystic ovaries and herbal remedies: A systematic reviewManouchehri A, et al. · JBRA assisted reproduction · 2023PMID 35916457 ↗06Inositol is an effective and safe treatment in polycystic ovary syndrome: a systematic review and meta-analysis of randomized controlled trialsGreff D, et al. · Reproductive biology and endocrinology : RB&E · 2023PMID 36703143 ↗Reported results grouped by condition. Values and units are preserved as recorded; missing information is not estimated.
How to read this table
Reported direction, numerical results and study design are separate. Certainty has not been formally graded in this table.
| What was measured | Reported findings | Result and units | Reported sample and duration | Study / source |
|---|---|---|---|---|
| Anxiety and obsessive-compulsive symptoms | Inositol did not significantly improve anxiety or obsessive-compulsive symptoms compared to placebo.No clear benefit | Not reported Recorded unit: Not reported | Sample (as reported): Not reported Follow-up: Not reported | Meta-analysis · 2014 Study detailsA meta-analysis of inositol for depression and anxiety disorders. Meta-Analysis |
| Depressive symptoms | Inositol did not significantly improve depressive symptoms compared to placebo.No clear benefit | Not reported Recorded unit: Not reported | Sample (as reported): Not reported Follow-up: Not reported | Meta-analysis · 2014 Study detailsA meta-analysis of inositol for depression and anxiety disorders. Meta-Analysis |
| Treatment discontinuation | Inositol did not significantly change discontinuation rates compared to placebo.No clear benefit | Not reported Recorded unit: Not reported | Sample (as reported): Not reported Follow-up: Not reported | Meta-analysis · 2014 Study detailsA meta-analysis of inositol for depression and anxiety disorders. Meta-Analysis |
| What was measured | Reported findings | Result and units | Reported sample and duration | Study / source |
|---|---|---|---|---|
| Nausea and tiredness | Inositol improved Nausea and tiredness (p = 0.02; p = 0.01) compared with fluvoxamine in Twenty (1 month). (p = 0.02; p = 0.01)Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): Twenty Follow-up: 1 month | Randomised trial · 2001 Study detailsDouble-blind, controlled, crossover trial of inositol versus fluvoxamine for the treatment of panic disorder. Randomized Controlled Trial |
| Number of panic attacks per week | Inositol improved Number of panic attacks per week (4.0 (2); 2.4 (2); p = 0.049) compared with fluvoxamine in Twenty (1 month). (p = 0.049)Benefit seen | 4.0 (2) Recorded unit: Not reported | Sample (as reported): Twenty Follow-up: 1 month | Randomised trial · 2001 Study detailsDouble-blind, controlled, crossover trial of inositol versus fluvoxamine for the treatment of panic disorder. Randomized Controlled Trial |
| Attention deficit disorder (ADDH) with hyperactivity symptomatology | Inositol 200 mg/kg body weight showed harm (adverse effect) on Attention deficit disorder (ADDH) with hyperactivity symptomatology compared with placebo in Eleven children (eight week).Possible harm | Not reported Recorded unit: Not reported | Sample (as reported): Eleven children Follow-up: eight week | Randomised trial · 1997 Study detailsControlled trials of inositol in psychiatry. Randomized Controlled Trial |
| Autism symptoms | Inositol 200 mg/kg per day did not significantly improve Autism symptoms in an uncontrolled study (no comparison group) in nine.No clear benefit | Not reported Recorded unit: Not reported | Sample (as reported): nine Follow-up: Not reported | Randomised trial · 1997 Study detailsControlled trials of inositol in psychiatry. Randomized Controlled Trial |
| ECT-induced memory impairment | Inositol 6 g daily did not significantly improve ECT-induced memory impairment in an uncontrolled study (no comparison group) in twelve (five days).No clear benefit | Not reported Recorded unit: Not reported | Sample (as reported): twelve Follow-up: five days | Randomised trial · 1997 Study detailsControlled trials of inositol in psychiatry. Randomized Controlled Trial |
| Frequency and severity of panic attacks and severity of agoraphobia | Inositol 12 g per day improved Frequency and severity of panic attacks and severity of agoraphobia compared with placebo in twenty-one (four week).Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): twenty-one Follow-up: four week | Randomised trial · 1997 Study detailsControlled trials of inositol in psychiatry. Randomized Controlled Trial |
| Hamilton Depression Scale | Inositol 12 g daily improved Hamilton Depression Scale compared with placebo in 28 (four weeks).Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): 28 Follow-up: four weeks | Randomised trial · 1997 Study detailsControlled trials of inositol in psychiatry. Randomized Controlled Trial |
| OCD symptoms scores | Inositol 18 g improved OCD symptoms scores compared with placebo in thirteen (six weeks each).Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): thirteen Follow-up: six weeks each | Randomised trial · 1997 Study detailsControlled trials of inositol in psychiatry. Randomized Controlled Trial |
| Schizophrenic symptoms | Inositol 12 g daily did not significantly improve Schizophrenic symptoms in an uncontrolled study (no comparison group) in twelve (a month).No clear benefit | Not reported Recorded unit: Not reported | Sample (as reported): twelve Follow-up: a month | Randomised trial · 1997 Study detailsControlled trials of inositol in psychiatry. Randomized Controlled Trial |
| Therapeutic effects in Alzheimer's | Inositol 6 g daily did not significantly improve Therapeutic effects in Alzheimer's compared with glucose; the difference versus the comparator was not statistically established in eleven (one month each).No clear benefit | Not reported Recorded unit: Not reported | Sample (as reported): eleven Follow-up: one month each | Randomised trial · 1997 Study detailsControlled trials of inositol in psychiatry. Randomized Controlled Trial |
| frequency and severity of panic attacks | Inositol improved frequency and severity of panic attacks compared with placebo in Twenty-one (4-week).Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): Twenty-one Follow-up: 4-week | Randomised trial · 1995 Study detailsDouble-blind, placebo-controlled, crossover trial of inositol treatment for panic disorder. Randomized Controlled Trial |
| severity of agoraphobia | Inositol improved severity of agoraphobia compared with placebo in Twenty-one (4-week).Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): Twenty-one Follow-up: 4-week | Randomised trial · 1995 Study detailsDouble-blind, placebo-controlled, crossover trial of inositol treatment for panic disorder. Randomized Controlled Trial |
| What was measured | Reported findings | Result and units | Reported sample and duration | Study / source |
|---|---|---|---|---|
| Acne score | Myo-inositol and D-chiro inositol significantly improved acne score compared with placebo over 6 months.Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): 137 Follow-up: 6 months | Randomised trial · 2015 Study detailsMyo-inositol vs. D-chiro inositol in PCOS treatment. Randomized Controlled Trial |
| Endocrine parameters | Myo-inositol and D-chiro inositol significantly improved endocrine parameters compared with placebo over 6 months.Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): 137 Follow-up: 6 months | Randomised trial · 2015 Study detailsMyo-inositol vs. D-chiro inositol in PCOS treatment. Randomized Controlled Trial |
| Insulin resistance | Myo-inositol and D-chiro inositol significantly improved insulin resistance compared with placebo over 6 months.Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): 137 Follow-up: 6 months | Randomised trial · 2015 Study detailsMyo-inositol vs. D-chiro inositol in PCOS treatment. Randomized Controlled Trial |
| Menstrual cycle regularity | Myo-inositol and D-chiro inositol significantly improved menstrual cycle regularity compared with placebo over 6 months.Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): 137 Follow-up: 6 months | Randomised trial · 2015 Study detailsMyo-inositol vs. D-chiro inositol in PCOS treatment. Randomized Controlled Trial |
| Metabolic parameters | Myo-inositol and D-chiro inositol significantly improved metabolic parameters compared with placebo over 6 months.Benefit seen | Not reported Recorded unit: Not reported | Sample (as reported): 137 Follow-up: 6 months | Randomised trial · 2015 Study detailsMyo-inositol vs. D-chiro inositol in PCOS treatment. Randomized Controlled Trial |
Associated conditions and community-reported outcomes, wrapped together on one page. Aggregates appear only once enough reports arrive.
How this compound is sold in the UK, and where our readers typically find it.
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