The effectiveness of a Chinese formula called ‘Tian gui fang’ in comparison with metformin was tested on patients with polycystic ovarian syndrome [PCOS].  The patients were divided into two groups and either Tian gui fang or metformin was administered for three months.  After treatment, 4 out of the 8 patients on metformin had restoration of menstrual cyclicity, and two of them had a double phase BBT.  The testosterone levels had decreased.  No other measures changed.  In the group that received the Chinese medicine, 6 patients out of 8 had a restored cycle as well as a double phase BBT.  Testosterone and the body mass index (BMI) decreased significantly.  The authors conclude that both therapies can induce ovulation but that Chinese herbal medicine has a higher efficacy in restoring ovulation and normal BBT measures. 

Hou J, Yu J, Wei M. ‘Study on treatment of hyperandrogenism and hyperinsulinism in polycystic ovary syndrome with chinese herbal formula ‘tian gui fang’. Zhongguo Zhong Xi Jie he Za Zhi. 2000; 20 (8):589.