Inclusion Criteria:  Females 18 years to 40 years of age Diagnosed as PCOS by the 2003 Rotterdam criteria Overweight/obesity (BMI≥24 kg/m2) No pregnant plan in recent 6 months Written consent for participation in the study  Exclusion Criteria:  type 1 or type 2 diabetes mellitus Subjects have other endocrine diseases, such as adrenal hyperplasias or tumor, androgen-secreting tumors, Cushing's syndrome, thyroid diseases, and hyperprolactinemia Diagnosed with or have a family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2) Serious systemic disease or malignant tumor History of pancreatitis (chronic, acute or recurrent) Body weight change ≥10% at 3 months before treatment Used oral contraceptives or sex hormone drugs in the past 1 month Used oral glucocorticoids in the past 1 month Substance (alcohol or drug) abuse or dependence within 3 months Heavy smokers (smokers who smoke 20 or more cigarettes a day) or heavy drinkers (>10g/d) Subjects have a severe systemic disease, such as cardiovascular system, Renal impairment (eGFR<60ml/min/1.73m2) Increase of transaminases up to < 2.5 times of upper limit of normal value Have a history of thromboembolic disease or thrombotic tendency Subjects in pregnant or lactating or within 1 year after delivery Subjects have an allergic history to the drugs used in the study Subjects have participated in other clinical researches of medicine within 1 month prior to randomization Use of metformin, glucagon-like peptide -1 receptor agonists, or weight loss medications (prescription or OTC) within 30 days before screening