Ovulation is a metabolic event
Inositol for Fertility:
The Studies
Ovulation is metabolic. High insulin pushes the ovaries toward androgen production and disrupts the signals that mature and release an egg. That's why an insulin-sensitizing molecule became one of the most-studied supplements for ovulatory function.*
Study 1 — 70% ovulated vs 21%
Study Background
The gold standard of research, applied directly to ovulation: 42 women with PCOS were randomly split — one group took myo-inositol, the other a placebo, and nobody, not even the researchers, knew who had which until the end (Costantino et al., 2009).†
Study Attributes
Placebo-Controlled
One group gets the real thing. The other gets a look-alike dummy — a placebo, here plain folic acid. Comparing the two shows what the compound actually does, beyond the effect of believing it works.
Double-Blind
Neither the women nor the researchers knew who was taking what until the study ended. That keeps hope and bias from skewing the results. This is the only blinded, placebo-controlled ovulation figure on this page — which is why it leads.
Randomized
Who got the real thing was decided by chance, like a coin flip. That keeps the two groups fair to compare.
Study 1 — The Results
MYO-INOSITOL VS PLACEBO
70%
of women taking myo-inositol ovulated during the study — versus 21% on placebo*†
women taking myo-inositol ovulated during the study*†
women taking placebo ovulated during the study*†
Myo-Inositol
Myo-inositol is the most common form of inositol in your body, and it's concentrated in the ovary — where it helps carry the signals that mature and release an egg.
Insulin and Ovulation
Too much insulin pushes the ovaries to make more testosterone and muddles the signals that mature an egg. Helping the body handle insulin better is how inositol is thought to support ovulation. In this trial, insulin response improved right alongside it.
†Study 1: Costantino D, Minozzi G, Minozzi E, Guaraldi C. Metabolic and hormonal effects of myo-inositol in women with polycystic ovary syndrome: a double-blind trial. Eur Rev Med Pharmacol Sci. 2009;13(2):105–110. PubMed PMID: 19499845. Independent study, not of Bodology.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Study 2 — Ten trials, one direction
Study Background
Zoom out. Researchers pooled ten separate trials — 601 women in total — to ask whether the ovulation results hold up across all of them. They do. (Pundir et al., 2018).‡
Study Attributes
Why the Journal Matters
BJOG is one of the highest-reputation obstetrics and gynaecology journals in the world. Peer review at this level is a meaningful quality bar — much of the supplement literature never clears it.
What a Meta-Analysis Is
A meta-analysis pools many separate trials into one answer, so no single study's quirks can skew the picture. This one pooled 362 women on inositol, 179 on placebo, and 60 on metformin.
Study 2 — The Results
TEN TRIALS, POOLED
2.3×
the likelihood of ovulating on inositol versus placebo, pooled across all ten trials*‡
more frequent periods on inositol than on placebo*‡
trials pointed the same direction on cycle frequency — rare agreement in supplement research*‡
Relative Risk (RR)
Relative risk compares how often something happens in one group versus another. Here: women on inositol were 2.3 times as likely to ovulate as women on placebo (95% CI 1.1–4.7), and periods came 6.8 times more frequently (95% CI 2.8–16.6).
Heterogeneity
Heterogeneity measures how much the trials in a pooled analysis disagree with each other. On cycle frequency it was zero — every one of the ten trials pointed the same way. That level of agreement is rare in supplement research.
‡Study 2: Pundir J, Psaroudakis D, Savnur P, Bhide P, Sabatini L, Teede H, Coomarasamy A, Thangaratinam S. Inositol treatment of anovulation in women with polycystic ovary syndrome: a meta-analysis of randomised trials. BJOG. 2018;125(3):299–308. DOI: 10.1111/1471-0528.14754. No trials in this analysis evaluated live-birth or miscarriage rates.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Study 3 — Egg quality & pregnancy
Study Background
149 women going through ICSI (a form of IVF) were randomly split: half added myo-inositol to their folic acid, half took folic acid alone. Egg quality, embryo grade, and pregnancy rate all came out better in the inositol group (Brusco & Mariani, 2013).§
Study Attributes
Randomized
Who got the inositol was decided by chance, like a coin flip. That keeps the two groups fair to compare.
Open-Label — Read This
"Open-label" means everyone knew who was taking what — a weaker design than double-blind. This trial also wasn't limited to women with PCOS, and it used myo-inositol alone rather than the 40:1 blend. We show it because the outcomes matter; we label it because the design does too.
Study 4 — The 40:1 blend in IVF
Study Background
Women with PCOS going through IVF were randomly given either the 40:1 blend or D-chiro-inositol on its own. Only the 40:1 blend improved egg quality, embryo quality, and pregnancy rates — the balance is what mattered (Colazingari et al., 2013).¶
Study Attributes
Randomized
Who got which was decided by chance, like a coin flip. That keeps the groups fair to compare.
The Comparison
1.1 g myo + 27.6 mg D-chiro — the same natural 40:1 balance used in Bodology — against 500 mg D-chiro-inositol alone. Only the 40:1 blend moved the results.
§Study 3: Brusco GF, Mariani M. Inositol: effects on oocyte quality in patients undergoing ICSI. An open study. Eur Rev Med Pharmacol Sci. 2013;17(22):3095–3102. PubMed PMID: 24302192. Open-label; not PCOS-only; myo-inositol (not the 40:1 blend). Percentages from the published tables; significance values from the abstract.
¶Study 4: Colazingari S, Treglia M, Najjar R, Bevilacqua A. The combined therapy myo-inositol plus D-chiro-inositol, rather than D-chiro-inositol, is able to improve IVF outcomes. Arch Gynecol Obstet. 2013;288(6):1405–1411. DOI: 10.1007/s00404-013-2855-3.
All four studies are independent research on inositol, not on Bodology. Inositol is not a fertility treatment. If you're trying to conceive, work with your clinician.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
