Polycystic ovary syndrome (PCOS),is a complex neuro-endocrine disorder affecting approximately 5% to 10% of women in reproductive age.Inositols are considered insulin sensitizers, as they modulate the members of insulin signaling pathways.Thiss study compares between the effect of inositol and metformin in letrozol resistant PCOS women.

Polycystic ovary syndrome (PCOS),is a complex neuro-endocrine disorder affecting approximately 5% to 10% of women in reproductive age .Furthermore, impaired glucose tolerance affects 30 - 40 % of women with PCOS and the pathophysiology of insulin resistance appears to be linked to a malfunction in the insulin signalling system. Insulin-sensitizing substances, including the B-complex vitamin inositol and its stereoisomers (myo-inositol and D-chiro-inositol )have therefore been investigated as a potential treatment for PCOS.

Letrozole is the recommended medication for ovulation induction in PCOS-related infertility since it produces higher pregnancy and live birth rates than Clomphine Citrate. Alternative regimens, such as two-step, higher, and prolonged doses, may be necessary for women who are not responding to the standard letrozole dosage. However, some women might not respond to letrozole even at the highest dosage.

Inositols are produced by the human body and are a member of the vitamin B complex group.Inositols are considered insulin sensitizers, as they modulate the members of insulin signaling pathways. They positively influence menstrual cycle regularity, carbohydrate metabolism, and the clinical and laboratory symptoms of hyperandrogenism (e.g., free testosterone, total testosterone, SHBG).

Inclusion Criteria:

• • Age between 18- 35 years old.

  • Diagnosis of PCOS according to Rotterdam criteria
  • Letrozole resistant cases.
  • Normal thyroid hormone level.
  • Normal prolactin hormone level.

Exclusion Criteria:

• • History of ovarian surgery.

  • cases associated with endometriosis.
  • History of diabetes mellitus.
  • Allergy to myo-Inositol .