A total of 128 subjects 20-80 years of age with a history of insomnia at least 1 month were recruited randomly assigned to SZRT (n = 48), placebo (n =32), TWBXD (n =48) and were instructed to take 6 gm 2 times per day of SZRT, TWBXD or placebo for a period of 4 weeks. The primary outcome measures were the mean component scores of the Pittsburgh Sleep Quality Index (PSQI). Secondary outcome parameter were the global score on the World Health Organization Quality of Life questionnaire - Taiwan brief version, drugs consumption counts, sleep diary and safety profiles by structures questionnaires.