Mood Support
Inositol
Also known as: 40:1 Inositol Blend, D-chiro-inositol, Inositol (Myo-Inositol), Inositol Blend
B vitamin-like compound particularly effective for PCOS, insulin sensitivity, and egg quality.
Last reviewed June 2026 · Evidence graded from peer-reviewed research, not editorial opinion. Educational only — not medical advice.
Every Inositol product we have scored
| # | Product | Score | Per serving |
|---|---|---|---|
| 1 | Pure Encapsulations Inositol (powder) | 94 A | $0.90 |
| 2 | Double Wood Inositol Supplement | 94 A | $0.50 |
| 3 | Jarrow Formulas Inositol - 750mg Veggie Capsules | 94 A | $0.19 |
| 4 | Natural Factors No Flush Niacin 500 mg | 93 A | $0.26 |
| 5 | Pure Encapsulations Inositol Complex | 90 A | $0.93 |
| 6 | Complement ForHer Hormone Balance and Longevity Multivitamin for Women | 89 A | $0.67 |
| 7 | NOW Foods Double Strength L-Theanine | 89 A | $0.20 |
| 8 | Nature's Way Inositol | 87 A | $0.16 |
| 9 | NOW Foods Phosphatidyl Serine | 87 A | $0.37 |
| 10 | NOW Foods Chewable L-Theanine, Berry | 87 A | $0.16 |
| 11 | Thorne Ovarian Care | 86 A- | $0.42 |
| 12 | Life Extension BioActive Complete B-Complex | 86 A- | $0.30 |
Scored on dose accuracy, form, label transparency and third-party testing. Per-serving cost is list price divided by servings per container. No brand pays to be listed or ranked.
Common questions
How much Inositol should I take?
The typical range is 2-18g daily (varies by condition). 4-6 weeks for anxiety
When should I take Inositol?
Divided doses. Either.
Which form of Inositol is best?
Powder — High doses needed. Other forms in the catalog: Capsule, Myo-inositol powder, 40:1 myo:D-chiro blend, Capsules, 40:1 blend.
Is Inositol safe?
Commonly reported: GI upset high doses, Nausea. Serious warnings: May worsen bipolar. No concerns
Which Inositol supplement scores highest?
Pure Encapsulations Inositol (powder), at 94/100. Scored on dose accuracy, form, label transparency and third-party testing — no brand pays to be listed or ranked.
Primary uses
- Anxiety
- OCD support
- PCOS
- Sleep
- Ovulation
- Insulin sensitivity
- Egg quality
- Androgen reduction
What systematic reviews concluded
Outcomes that systematic reviews of Inositol reached a verdict on: 4 with a benefit, 2 with no effect, 3 unclear. Each is quoted from a review and linked to it on PubMed. How these were read.
Reviews found a benefit (4)
“Inositol supplementation is associated with improvements in biochemical hyperandrogenism in women with PCOS, with evidence of phenotype-dependent variability.” PMID 41947399
“Chromium, inositol, and Omega-3 were found to be beneficial for improving lipid profile.” PMID 40611279
“Our results suggest that MI supplementation improves the MII oocyte rate and the fertilization rate.” PMID 40190407
“During IVF, MI is effective in both PCOS and non-PCOS women in saving gonadotropins, but reduces efficiently SL only in PCOS women.” PMID 30078122
Reviews found no effect (2)
“the use of Myo-inositol, Vitamin D alone, and the combination of selenium, and Myo-inositol did not effectively reduce TPOAb (Myo-inositol: SMD:-1.94, 95% CI: -6.75, 2.87; Vitamin D: SMD: -2.54, 95% CI: -6.51,1.42; Se+Myo-inositol: SMD: -3.01, 95% CI: -8.96,2.93) or TgAb (Myo-inositol: SMD:-2.02, 95% CI: -6.52, 2.48; Vitamin D: SMD: -2.73, 95% CI: -6.44,0.98; Se+Myo-inositol: SMD: -3.64, 95% CI: -9.20,1.92) levels.” PMID 39698034
“the use of Myo-inositol, Vitamin D alone, and the combination of selenium, and Myo-inositol did not effectively reduce TPOAb” PMID 39698034
Not enough to say: female infertility outcomes; insulin resistance; female subfertility outcomes.
12 findings from reviews in specific patient groups (such as cancer, pregnancy or surgery) are not shown here.
How it works
- Second messenger in serotonin system
- Insulin signaling support
Dosage
- Typical range
- 2-18g daily (varies by condition)
- Timing
- Divided doses
- With food
- Either
- Duration
- 4-6 weeks for anxiety
- Special populations
- Anxiety, OCD, PCOS
Forms
- Powder
- Capsule
- 40:1 myo:D-chiro blend
- Capsules
- 40:1 blend
Safety
Common side effects
- GI upset high doses
- Nausea
Contraindications
- Bipolar (may trigger mania)
Products containing Inositol
Top-scoring supplements in our catalog that list Inositol on the label. Each product is graded on Formulate's ingredient-level rubric — dose accuracy, form, transparency, and third-party testing.
Evidence notes
Strong evidence for PCOS and ovulation improvement
Grade A: Multiple well-designed human trials support the main claims.
Related in Mood Support
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Medical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider. Individual needs and risks vary — consult a professional before starting, stopping, or combining supplements, especially if you are pregnant or nursing, taking medication, or managing a health condition.