Can Inositol Increase Fertility?

Originally published 07/28/2021. Updated for accuracy and relevancy on 12/07/2023

You’ve read the lists of helpful fertility support and prenatal supplements, and you know the basics: prenatal vitamins, CoQ10, folate, but where does myo-inositol fertility treatment fit in?

By OBGYN and fertility expert Dr Kenosha Gleaton

A member of the vitamin B complex, inositol is a naturally occurring substance with antioxidant properties. Some studies have suggested that inositol can be beneficial for improving IVF outcomes and general female fertility, especially for those with polycystic ovarian syndrome (PCOS).

Ovulation and Ovarian Function

A randomized, double-blind clinical trial found a beneficial effect of myo-inositol supplementation in improving ovarian function in women with oligomenorrhea (aka infrequent menstrual periods) and polycystic ovaries (a hormonal disorder causing enlarged ovaries with small cysts).¹ The double-blind, randomized control study found that women who took myo-inositol ovulated more frequently than the placebo group.

Another study of 91 PCOS women found that the combination of inositol and folic acid may promote ovulation in women with fertility issues.²

Does Myo-inositol (MI) Improve Egg Quality?

There have been established antioxidant and growth-promoting factors of MI.³ Some studies have shown improved embryo and oocyte quality as well as improved overall ovulary function as a result of MI supplementation.^1,2 The ovary also uses high levels of MI to help carry out physiological activities and is thought to increase insulin sensitivity of the ovary to potentially improve egg quality.⁴

Myo-Inositol and IVF

One systematic review suggests that Myo-Inositol supplementation is able to reduce the amount of gonadotropins (a fertility medication used during IVF) used in both PCOS and non-PCOS women undergoing IVF.⁵ Additionally, the authors found MI was able to reduce the IVF cycle length for women with polycystic ovarian syndrome (meaning fewer trigger shots and less money!).

Another meta-analysis and systematic review of seven trials with 935 women found that MI may improve embryo quality, help reduce the amount of unsuitable oocytes, and decrease the amount of needed stimulation drugs.⁶ It was also found to increase the clinical pregnancy rate in women with infertility issues undergoing IVF.

How Much Inositol Should I Take for Fertility?

A study focused on ovarian function in women with PCOS showed favorable results after giving a dosage of 200 mg of inositol, two times a day, for 12 months.^2,7 Another study used a dosage of 4,000 mg/day and observed better fertilization rates and improved embryo quality.^2,7

The short answer: there aren’t enough studies on myo-inositol fertility rates to know exactly how much to take or how effective it is. We recommend talking with your OBGYN or REI about if you’re interested in taking inositol or any fertility supplement. 

How Long Does Inositol Take to Work for Fertility?

There isn’t an agreed upon time frame for inositol supplementation to begin showing effects, but many studies have observed positive effects on female fertility after 3 to 4 months.^1,2 Most supplementation before IVF treatments begins around 2 to 3 months prior to treatment.^8,2

The Ratio of Myo-Inositol (MI) to D-Chiro Inositol (DCI) in Your Supplement Matters

Each organ has a specific MI/DCI ratio related to its function. In the ovary, MI enhances the action of FSH, via anti-Müllerian hormone (AMH), and DCI is responsible for an excess production of insulin-dependent testosterone.⁹ According to scientists, MI has been found in follicular fluid and appears to improve oocyte and embryo quality.

Clinical evidence has demonstrated that a 40:1 ratio between MI and DCI is the optimal combination for the most effective results.^4,10-13

To Sum It Up...

Emerging data on inositol for fertility is compelling, especially for women struggling with PCOS. As a member of the vitamin B complex family, inositol is a naturally occurring substance with antioxidant properties. Some clinics and fertility doctors may prescribe or suggest inositol for ovulation or IVF. Additionally, taking inositol for sleep is also beneficial. It is always best to talk to your doctor before starting any supplement regimen.

Sources:

1. Gerli S, Mignosa M, Di Renzo GC. Effects of inositol on ovarian function and metabolic factors in women with PCOS: a randomized double blind placebo-controlled trial. European Review for Medical and Pharmacological Sciences. 2003;7(6):151-159. https://www.ncbi.nlm.nih.gov/pubmed/152064842.
2. Regidor PA, Schindler AE, Lesoine B, Druckman R. Management of women with PCOS using myo-inositol and folic acid. New clinical data and review of the literature. Hormone molecular biology and clinical investigation. 2018;34(2):/j/hmbci.2018.34.issue2/hmbci2017-0067/hmbci2017-0067.xml. doi:https://doi.org/10.1515/hmbci-2017-00673.
3. Chhetri DR. Myo-Inositol and Its Derivatives: Their Emerging Role in the Treatment of Human Diseases. Frontiers in Pharmacology. 2019;10. doi:https://doi.org/10.3389/fphar.2019.011724.
4. Roseff S, Montenegro M. Inositol Treatment for PCOS Should Be Science-Based and Not Arbitrary. International Journal of Endocrinology. 2020;2020. doi:https://doi.org/10.1155/2020/64612545.
5. Laganà AS, Vitagliano A, Noventa M, Ambrosini G, D’Anna R. Myo-inositol supplementation reduces the amount of gonadotropins and length of ovarian stimulation in women undergoing IVF: a systematic review and meta-analysis of randomized controlled trials. Archives of Gynecology and Obstetrics. 2018;298(4):675-684. doi:https://doi.org/10.1007/s00404-018-4861-y6.
6. Zheng X, Lin D, Zhang Y, et al. Inositol supplement improves clinical pregnancy rate in infertile women undergoing ovulation induction for ICSI or IVF-ET. Medicine. 2017;96(49):e8842. doi:https://doi.org/10.1097/md.00000000000088427.
7. Sacchinelli A, Venturella R, Lico D, et al. The Efficacy of Inositol and N-Acetyl Cysteine Administration (Ovaric HP) in Improving the Ovarian Function in Infertile Women with PCOS with or without Insulin Resistance. Obstetrics and Gynecology International. 2014;2014:1-5. doi:https://doi.org/10.1155/2014/1410208.
8. Simi G, Genazzani AR, Obino MER, et al. Inositol and In Vitro Fertilization with Embryo Transfer. International Journal of Endocrinology. 2017;2017:1-5. doi:https://doi.org/10.1155/2017/54694099.
9. Merviel P, James P, Bouée S, et al. Impact of myo-inositol treatment in women with polycystic ovary syndrome in assisted reproductive technologies. Reproductive Health. 2021;18(1). doi:https://doi.org/10.1186/s12978-021-01073-310.
10. Benelli E, Del Ghianda S, Di Cosmo C, Tonacchera M. A Combined Therapy with Myo-Inositol and D-Chiro-Inositol Improves Endocrine Parameters and Insulin Resistance in PCOS Young Overweight Women. International Journal of Endocrinology. 2016;2016:1-5. doi:https://doi.org/10.1155/2016/320408311.
11. Wojciechowska A, Osowski A, Jóźwik M, Górecki R, Rynkiewicz A, Wojtkiewicz J. Inositols’ Importance in the Improvement of the Endocrine–Metabolic Profile in PCOS. International Journal of Molecular Sciences. 2019;20(22):5787. doi:https://doi.org/10.3390/ijms2022578712.
12. Kamenov Z, Gateva A. Inositols in PCOS. Molecules. 2020;25(23):5566. doi:https://doi.org/10.3390/molecules2523556613.
13. M N, E P. The Combined Therapy With Myo-Inositol and D-chiro-inositol Reduces the Risk of Metabolic Disease in PCOS Overweight Patients Compared to Myo-Inositol Supplementation Alone. European review for medical and pharmacological sciences. Published May 1, 2012. https://pubmed.ncbi.nlm.nih.gov/22774396/