In some of the industrialized nations, regulators and health professionals have already come to terms with the challenge of evaluating and regulating herbs and phytomedicines (Akerele, 1992; Blumenthal, 1994). In 1991 WHO published its "Guidelines for the Assessment of Herbal Medicines" in recognition of the worldwide growth in the use of herbs in both official and unofficial medicine. The main purpose was to aid member nations in establishing appropriate regulatory criteria and procedures to evaluate the quality, safety, and efficacy of herbal medicines.

The guidelines call for the recognition that long-term historical use of a botanical in traditional medicine constitutes a presumption of safety unless contradicted by modern scientific research:

A guiding principle should be that if the product has been traditionally used without demonstrated harm, no specific regulatory action should be undertaken unless new evidence demands a revised risk-assessment....As a basic rule, documentation of a long period of use should be taken into consideration when safety is being assessed. This means that, when there are no detailed toxicological studies, documented experience on long-term use without evidence of safety problems should form the basis of the risk assessment. However, even in cases of long-used drugs, chronic toxicological risks may have occurred, but may not have been recognized. If available, the period of use, the health disorders treated, the number of users, and the countries with experience should be specified. If a toxicological risk is known, toxicity data have to be submitted. Risk assessment, whether it is independent of dose (e.g., special danger of allergies), or whether it is a function of dose, should be documented. In the second instance the dosage specification must be an important part of the risk assessment. An explanation of the risks should be given, if possible. The potential for misuse, abuse, or dependence has to be documented. If long-term traditional use cannot be documented, or doubts on safety exist, toxicity data should be submitted (WHO, 1991).

Regarding establishing efficacy, WHO guidelines state:

The indication(s) for the use of the medicine should be specified. In the case of traditional medicines, the requirements for proof of efficacy shall depend on the kind of indication. For treatment of minor disorders and for nonspecific indications, some relaxation is justified in the requirements for proof of efficacy, taking into account the extent of traditional use; the same considerations apply to prophylactic use. [Emphasis added.] Experience with individual cases recorded in reports from physicians, traditional health practitioners, or treated patients should be taken into account. Where traditional use has not been established, appropriate clinical evidence should be taken into account (WHO, 1991).

WHO guidelines also called for the establishment of monographs to determine the identity, quality, and therapeutic information on herbal medicines (Akerele, 1992). WHO monographs contain standards for determining the identity and purity of herbal drugs as well as detailed information on the therapeutic aspects of the herbs. The first set of 28 WHO monographs covering 41 species is to be published in 1998 (Blumenthal, 1997).