<qa>  What is the gold standard to test the efficacy of intervention?It is well known that randomized controlled trial RCT is the gold standard to test the efficacy of intervention, thus in this project, we attempt to follow the basic requirements of RCT to testify the efficacy and safety of CHM on FC, as well as to determine the optimal dosage. We believe such study will benefit the advancement of CHM, or even as the foundation of research study in future. 