Polycystic ovary syndrome (PCOS) is the most common endocrine and metabolic disorders in women of reproductive age, and its prevalence rate is from 9% (NIH criteria) to 18% (Rotterdamcriteria). It is clinically characterized by hyperandrogenism, persistent anovulation, and polycystic ovarian changes. Moreover it is often accompanied by insulin resistance and obesity. Now, metformin is not only an antihyperglycemic drug, it also corrects insulin resistance and hyperandrogenism in polycystic ovary syndrome. Chiglitazar is a novel peroxisome proliferation activated receptor (PPAR) agonist. Treatment of type 2 diabetes mellitus by moderate activation of PPARα, PPARγ and PPARδ, improving insulin sensitivity, regulating blood glucose, and promoting fatty acid oxidation and utilization. However, there is limited evidence for its treatment of insulin resistance in women with PCOS. Therefore, investigators applied chiglitazar and metformin to two groups of PCOS patients to understand their effects on insulin resistance.

Inclusion Criteria:

1. Female aged 18- 45 years old
2. Normal weight BMI 18.5--24
3. Diagnosis of hyperandrogenism T>0.481ng/ml
4. The diagnosis of PCOS is based on the diagnostic criteria established by the Rotterdam consensus
5. No use of drugs affecting reproductive endocrine in the 3 months prior to the clinic visit

Exclusion Criteria:

1. T level is within the normal range
2. Organ dysfunction
3. Drugs that can affect endocrine such as contraceptives and steroids taken in the past 3 months
4. Confirmed diagnosis of diabetes
5. Are on a diet, use weight-affecting medications, or have experienced a weight change of >4.5kg within 3 months prior to the start of the study
6. Have other endocrine disorders, such as thyroid dysfunction, adrenal gland disease, hyperprolactinemia, etc.
7. Combined psychiatric disorders and severe primary diseases
8. Allergy to the drug or components of this study
9. Those who do not follow the doctor's instructions during the medication, or discontinue the treatment due to serious adverse reactions