Abstract: Herbal and other traditional pharmacologic therapies are in widespread use throughout the world. Such widespread use suggests, but does not assure, that traditional medicines have a favourable risk-benefit ratio. The actual benefits and risks remain to be evaluated by clinical trials supported and conducted according to the principles of modern clinical science. International organizations and national authorities have published statements for supporting clinical trials of herbal products, while these statements tend to be broad in their coverage, in addition, national statements focus on the regulatory requirements and languages of individual countries. Therefore, WHO-TDR released clear and concise recommendations for the data needed to support clinical trials in which herbal products are evaluated for diagnosis or treatment of diseases.

Key words: WHO, clinical trial, herbal products