Polycystic ovary syndrome (PCOS) is a common reproductive disease associated with endocrine and metabolic disorders. Some studies have shown that Chinese herbal medicine is beneficial for PCOS, but the efficacy of Chinese herbal medicine in the treatment of PCOS is not clear, because the quantity of pre-clinical data was limited and the quality of clinical evidence was variable. Therefore, this randomized double-blind placebo-controlled trial aim to evaluate the efficacy of Chinese herbal medicine (Bushen Huatan Decoction) in women with PCOS.

Inclusion Criteria:

1. The diagnosis of PCOS is based on the Rotterdam criteria.
2. Meet the syndrome differentiation standard of kidney-yang deficiency with phlegm-dampness and blood stasis in TCM theory.
3. women aged 18-40 years without fertility requirements.
4. A willingness to undergo this treatment plan.

Exclusion Criteria:

1. Hyperprolactinemia (2 times serum prolactin levels of more than 25 ng/ml at least one week apart).
2. Diminished ovarian reserve, FSH (follicle-stimulating hormone) level more than 10 IU/L.
3. Abnormal thyroid function, TSH (thyroid stimulating hormone) level less than 0.2 mIU/mL or more than 5.5 mIU/mL.
4. Suspected Cushing's syndrome.
5. Adrenal or ovarian tumors secreting androgen.
6. Poorly controlled type II diabetes.
7. Pregnancy or lactation.
8. Hypertensive patients with poorly controlled blood pressure (a systolic blood pressure more than 160 mmHg or a diastolic blood pressure more than 100 mmHg).
9. Those who had taken hormones or other drugs during the previous 3 months.
10. Acute heart, liver, kidney or blood diseases.