Table 1.

Characteristics of methods used in 22 reviewed studies

Name and year	Study design	Herb assayed	Control group	Blinding	Randomisation	Sample size discussed
Mathijssen, 20025	Before and after	No	No	No	No	No
Markowitz, 200016	Before and after	Yes	No	No	No	No
Burstein, 200014	Before and after	Yes	No	No	No	No
Durr, 200020	Before and after	No	No	No	No	No
Piscitelli, 200021	Before and after	Yes	No	No	No	No
Mai, 20037	Before and after	Yes	No	No	No	Yes
Hebert, 200423	Before and after	Yes	No	No	No	No
Bauer, 20036	Before and after	Yes	No	No	No	Yes
Hall, 20038	Before and after	Yes	No	No	No	Yes
Jiang, 200422	Before and after	Yes	No	No	Yes	Yes
Johne, 20024	Before and after	Yes	No	No	No	Yes
Wang, 200110	Before and after	Yes	No	No	No	Yes
Wang, 20029	Before and after	Yes	No	No	No	No
Markowitz, 200324	Before and after	No	No	No	No	Yes
Dresser, 200325	Before and after	No	No	No	No	No
Roby, 200111	Before and after	Yes	No	No	No	No
Wenk, 200412	Before and after	No	No	No	No	No
Sugimoto, 200115	Crossover	No	Yes (placebo)	Yes	Yes	No
Pfrunder, 200317	Crossover	Yes	Yes	No	Yes	No
Wang, 200418	Crossover	No	Yes (placebo)	Yes	Yes	No
Morimoto, 200419	Crossover	Yes	No	No	No	No
Johne, 199913	Parallel	Yes	Yes (placebo)	Yes	No	Yes