The effectiveness of inositol and metformin on infertile polycystic ovary syndrome women with resistant to letrozole

  • Sajadeh Pourghasem
  • Fatemeh Bazarganipour
  • Seyed Abdolvahab Taghavi
  • Maryam Azizi KutenaeeEmail author
Gynecologic Endocrinology and Reproductive Medicine



The purpose is a comparison of effectiveness of myo-inositol and metformin in infertile women with polycystic ovary syndrome (PCOS) treated with letrozole.


This study is a randomized single-blind controlled clinical trial undertaken in 150 infertile PCOS women. For all patients, letrozole is prescribed at a dose of 7.5 mg per day from the third day of menstruation for 5 days. Patients who did not ovulate were included and divided into three pretreatment groups: group I(control group), 200 µg of folic acid (as a placebo); group II, 1500 mg of metformin daily plus 200 µg of folic acid, and group III, inositol 2 g plus 200 µg of folic acid received twice daily for 3 months. In the last cycle, 7.5 mg letrozole was prescribed for the induction of ovulation. Primary outcomes were ovary function and pregnancy.


The ovarian function was not significantly different in those groups, whereas the ovarian function of inositol + folic acid group in normal BMI found significantly higher than other BMI spectra. In addition, the ovarian function is significantly higher in the inositol + folic acid group by increasing the infertility duration. The incidence of pregnancy is lower in letrozole + folic acid + inositol group than the other groups; however, it is not significant.


The addition of inositol and metformin to the treatment of infertile PCOS women with letrozole resistance improves the ovarian function; however, it is not significant. Of note, inositol was more effective than metformin in patients with normal BMI.

IRCT registration number



Infertility Inositol Metformin letrozole PCOS 


Author contributions

SP: data acquisition, conception and design; writing and confirming the final draft. FB: revise, reading, English diting and confirming the final revised manuscript. SAT: Conception and design; writing and confirming the final draft. MAK: Recording the outcomes; providing resources, reading and confirming the final draft


This study was funded by a grant from Hormozgan University of Medical Sciences (Grant number: 4675).

Compliance with ethical standards

Conflict of interest

The authors have any conflict of interest to declare regarding the manuscript.

Ethical approval

All procedures in the current study were in accordance with the ethical standards of the Hormozgan University of Medical with the 1964 Helsinki declaration.

Informed consent

All the participants provided their informed written consents before inclusion in the study.


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Mother and Child Welfare Research CenterHormozgan University of Medical SciencesBandar AbbasIran
  2. 2.Midwifery Department, School of MedicineYasuj University of Medical SciencesYasujIran
  3. 3.Gynecologic and Obstetrics Department, School of MedicineYasuj University of Medical SciencesYasujIran
  4. 4.Fertility and Infertility Research CenterHormozgan University of Medical SciencesBandar AbbasIran

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