Background: There is an increase in the prevalence of obesity-related reproductive disorders, particularly anovulation and infertility so , this indicate use of insulin sensitizing agents such as metformin and use of weight reduction agents such as orlistat in order to achieve reduction of BMI, reduce androgenic effect and improve ovulation . To the best of our knowledge, no studies in this respect was performed in Zagazig University before.

Aim: To asses the effect of orlistat versus metformin on improvement of ovulation rate, weight loss and lipid and hormonal profile.

Patients and methods: This randomized controlled trial was conducted at Zagazig University Hospital's outpatient clinic on 132 patients diagnosed with polycystic ovary syndrome. All cases were subjected to full history taking including, general examination and laboratory investigations including FSH, LH, TSH, free T4, free testosterone and prolactin level.

Results: There was no statistical significant difference between both groups as regard ovulation rate. There was significant changes between studied groups at 1st and 3rd month as regard anthropometric data except BMI was insignificant at 1st month. Also, there was significant difference between studied groups as regard to laboratory data at 1st and 3rd month except FSH at 3rd month was insignificant.

Conclusion: We advise choosing metformin as a safe and effective treatment over orlistat for the treatment of polycystic ovarian syndrome, preferably in conjunction with weight loss and a healthy lifestyle.