The investigators analyzed collection data of 10 years for the efficacy of metformin on body mass, menstrual frequencies, metabolic and hormonal outcomes in women with polycystic ovary syndrome (PCOS) and BMI ≥ 25kg/m2.

Each patient's age and height were recorded at baseline. In addition each patient weight, waist circumference, menstrual regularity, fasting glucose, glucose after 120 minute oral glucose tolerance test, luteinizing hormone, follicle stimulating hormone , free and direct testosterone, androstenedione, sex hormone binding globulin, dehydroepiandrosterone sulfate were identified at baseline and at the every follow up visit where available.

Inclusion Criteria:

• PCOS phenotype A
• BMI≥ 25kg/m2
• metformin 1000mg twice a day for at least one year

Exclusion Criteria:

• PCOS phenotype B, C, D
• BMI <25kg/m2
• had been treated with spironolactone or oral contraceptives alone or in combination with metformin
• had history of bariatric surgery
• became pregnant during the observation period
• had inability to tolerate metformin, leading to the cessation of drug therapy within first follow up year

Collection data from endocrine outpatient clinic for 10 years of women with PCOS phenotype A, BMI≥ 25kg/m2, all receiving monotherapy with metformin 1000 mg twice a day.