ABSTRACT
In the United States, medicinal herbs are categorized and regulated as botanical dietary supplements according to the Dietary Supple ment and Health Education Act (DSHEA, 1994). The intent of this legislation was to make more nutritional and botanical supplement al ternatives available to Americans, in order to improve public health and reduce future health care costs (DSHEA, 1994; Nesheim, 1999). Recently, use of botanical and dietary supplements by the American public has risen by an estimated 380 percent (Eisenberg et al., 1998), to sales exceeding $600 million (Brevoort, 1998). Yet under DSHEA legislation, the quality of plant medicines is ill defined and little guid ance is available to growers, processors, distributors, health care pro viders, or consumers specifically interested in understanding, main-
taining, or improving the quality of medicinal herbs as tools to improve health (Matthews et al., 1999).
