Table 2.

Adverse events of included studies.

Author, year	Size (T/C)	Nausea and vomiting (T/C)	Constipation (T/C)	Gastrointestinal discomfort (T/C)	Headache (T/C)	Allergic reaction (T/C)
Chen, 2018 [11]	66/66	3/2	13/14	10/11	1/2	2/1
Xue, 2020 [18]	46/46	—	—	4/3	0/1	2/2
Zhao, 2019 [23]	35/35	—	—	1/1	4/3	—
Zheng, 2018 [24]	30/30	—	—	2/2	—	—