Table 2 Adverse events of included trials

Pi 2006 [13]

Two menstrual disorders

Five drowsiness

Zhang 2007 [14]

Eight drowsiness, sleepiness and fatigue, gastrointestinal disorder, menstrual disorders

Five drowsiness, dry mouth, dizzy

Bao 2008 [15]

Seven drowsiness, sleepiness and fatigue, dry mouth; two gastrointestinal disorder, menstrual disorders

Five drowsiness, sleepiness and fatigue, dry mouth

Xu 2009 [16]

Five drowsiness, sleepiness and fatigue, dry mouth; one irregular menses, abnormal liver function

Four drowsiness, dizzy; two gastrointestinal disorder

Wei 2010 [17]

Three drowsiness, sleepiness and fatigue, dry mouth; two gastrointestinal disorder; one headache, dizzy; one menstrual disorders, abnormal liver function

Three drowsiness, sleepiness and fatigue, dry mouth; two gastrointestinal disorder; two headaches, dizzy;

Zhong 2011 [18]

Four cases including drowsiness, sleepiness and fatigue, gastrointestinal disorder

Five cases including drowsiness, sleepiness and fatigue, gastrointestinal disorder

Liu 2011 [19]

Two drowsiness; one sleepiness and fatigue; three gastrointestinal disorder; one bloating; two menstrual disorders

Two drowsiness; two dry mouth; one dizzy;

Qian 2011 [9]

Four gastrointestinal disorder; three dizzy; three insomnias; three palpitation; three alopecia

Seven drowsiness; one dizzy; one general malaise

Yu 2011 [20]

One gastrointestinal disorder; one dizzy

Two headaches, gastrointestinal disorder

Lu 2012 [21]

Two drowsiness; one sleepiness and fatigue; two gastrointestinal disorder; one dry mouth

One drowsiness; one sleepiness and fatigue; two dry mouth

Zhou 2012 [22]

10 gastrointestinal disorder; three abnormal liver functions

No significant side effects.

Fan 2013 [23]

Two drowsiness; three sleepiness and fatigue; two dizzy

Two drowsiness; two sleepiness and fatigue; two dizzy

Liu 2013 [24]

Nine drowsiness; two dry mouth

11 drowsiness; three dry mouth

Zheng 2013 [25]

One drowsiness; one sleepiness and fatigue; one gastrointestinal disorder; one headache

One dizzy; one gastrointestinal disorder; one dry mouth

Chen 2014 [26]

Two drowsiness, sleepiness and fatigue; four gastrointestinal disorder;

Four drowsiness, sleepiness and fatigue;

Wang 2014 [27]

One drowsiness; one sleepiness and fatigue; one gastrointestinal disorder

One drowsiness; one sleepiness and fatigue; two gastrointestinal disorder

Zhou 2014 [28]

Two drowsiness, sleepiness and fatigue, dry mouth; one gastrointestinal disorder; one headache, dizzy; one abnormal liver function

Two drowsiness, sleepiness and fatigue, dry mouth; one gastrointestinal disorder; one headache, dizzy;

Li 2016 [29]

One dizzy

Three drowsiness; one sleepiness and fatigue; one dizzy

Liu 2016 [30]

Three drowsiness; two gastrointestinal disorder; two dizzy

One drowsiness; two gastrointestinal disorder; one dizzy

Chen 2017 [31]

One headache, dizzy; one gastrointestinal disorder

One drowsiness; two headaches, dizzy; one gastrointestinal disorder

Tao 2017 [32]

Three drowsiness, sleepiness and fatigue; five gastrointestinal disorder;

Five drowsiness, sleepiness and fatigue;