Herbs have migrated to the health food stores, mail order establishments, and discount stores. Sales clerks do not generally give out much information because such activity could result in the unlicensed practice of medicine. The customer is usually referred to information sources such as natural medicine books. With the lack of regulation comes the problem with labeling. Packages are labeled with the common name only.
Popular names are numerous and inexact.
Snakeroot can be applied to six different plants. Ginseng can be oriental, wild red American, Korean, Chinese etc. There is little on the label and little regulation in regards to the potency or purity. Therefore brand 'x' could contain more herbs than brand 'z' but the consumer would never know. All of this is not to say that herbs are bad.