- Format
- Capsules
- Labelled serving / instructions
- 4 capsules per serving; manufacturer instructions allow 1–2 servings/day
- Inositol per serving
- 2,000 mg myo-inositol + 50 mg D-chiro-inositol
- Approx. cost per day
- $0.93–$1.86/day · 1–2 labelled servings/day · checked October 10, 2026
- Testing & quality sources
- View the documented source
Compare inositol.
Understand the evidence.
Compare supplements for PCOS by format, label amounts, quality information and cost. Find the trade-offs that matter to your routine.
Four questions. No account needed.
Start with the label, not the ranking
A closer look at three featured formulas. These are editorial selections, not a universal best-to-worst list.
Cost uses the stated number of labelled servings per day, before shipping or tax. Prices checked more than 90 days ago need a recheck. Formulas and retailer prices can change.
- Format
- Unflavoured powder
- Labelled serving / instructions
- 1 scoop or packet per serving; manufacturer directs 2 servings/day
- Inositol per serving
- 2,000 mg myo-inositol + 50 mg D-chiro-inositol
- Approx. cost per day
- $0.96/day · 2 labelled servings/day · checked October 10, 2026
- Testing & quality sources
- View the documented source
- Format
- Capsules
- Labelled serving / instructions
- 4 capsules daily / 1 serving
- Inositol per serving
- 2,000 mg myo-inositol + 50 mg D-chiro-inositol
- Approx. cost per day
- $0.83/day · 1 labelled serving/day · checked October 10, 2026
- Testing & quality sources
- View the documented source
How we compare
Researched by the Eco Hormone Balance Editorial Team. Our reviews are desk research, not independent laboratory testing.
Read our editorial method- Evidence & label amounts
- We separate study findings from product claims and compare the stated amounts per serving.
- Quality information
- We look for traceable testing and manufacturing sources, and identify what we cannot verify.
- Cost & daily routine
- Powder or capsules, serving burden, added ingredients and dated prices all affect practical fit.
- Safety & uncertainty
- Discuss supplements with a qualified clinician during pregnancy, fertility treatment or when taking medication. Read the disclaimer.
What the evidence can tell you
Inositol is involved in cell signalling. Myo-inositol and D-chiro-inositol are sold alone or together as powders and capsules.
A 40:1 formula is common, but PCOS guidance does not establish one type, dose or combination as best for everyone. A supplement label is not evidence that the product itself improves fertility.
Understand inositol and its limitsYou may also see the newer name polyendocrine metabolic ovarian syndrome (PMOS). We retain PCOS in existing guides so they remain easy to find. See the international guideline programme.
Read before you choose
All guides
Best Inositol for PCOS: 5 Formulas Compared
Compare five inositol products for PCOS by formula, capsule burden, added nutrients, testing transparency and cost—with no fertility hype.
What Is the 40:1 Ratio for Inositol? A Practical Guide
A 40:1 ratio means forty parts myo-inositol to one part D-chiro-inositol. It describes proportions, not a recommended dose or proof of better PCOS outcomes.
Powder vs Capsules: Which Inositol Format Is Better?
Powder and capsules change how you measure, prepare and take inositol. Compare the actual formula and labelled daily amount before treating the formats as equivalent.
Questions, with the limits included
What is inositol, and what may it help with in PCOS?
Inositol is a nutrient-like compound found in the body and in some supplements. Studies in PCOS report possible changes in selected metabolic or cycle-related outcomes, but current guidance does not establish a universal product, ratio, dose, or fertility benefit.
Is a 40:1 inositol ratio proven to be the best?
A 40:1 myo-inositol-to-d-chiro-inositol ratio is common and has been studied, but it has not been established as the best option for everyone. Compare the exact amounts, added ingredients, quality information, cost, and any clinician advice rather than relying on the ratio alone.
How long do studies usually measure inositol outcomes?
Research commonly measures different outcomes over several weeks to several months. That is a study window, not a promise or a deadline: response is uncertain, and fertility outcomes do not have a proven inositol timeline.
How do you compare supplement products?
We compare label amounts and forms, daily capsule or scoop burden, added nutrients, quality verification, price per labelled serving, manufacturer transparency, and the strength and limits of the evidence. Affiliate commission does not decide which products we include or how we describe them.
How does Eco Hormone Balance make money?
We do not sell supplements directly. Some product links are affiliate links, which means we may earn a commission if you buy through them, at no extra cost to you. That commercial relationship is disclosed near relevant links.
Is this medical advice, and who reviews the content?
No. Our articles are educational and evidence-informed, not individualized medical advice. The Eco Hormone Balance Editorial Team researches and reviews content using published evidence, current product labels, and a documented methodology. Editorial Policy documents our standards.
Brands we’ve reviewed
All reviewed brandsBrowse reviewed brands. Inclusion does not imply a partnership or endorsement.
Books on PCOS, nutrition and fertility
Explore our reading list, with notes on each book and links to related guides.
Browse the book library
Homepage updated . This date refers to the page, not a new verification of every product or price.