As the various traditions of herbal medicine have their roots in many different cultures and have only recently been investigated scientifically, it must be recognized that knowledge about herbal remedies is apt to be still perpetuated by oral tradition and found in anecdotal observations rather than in systematic laboratory and clinical studies that have been published in the scientific literature. Furthermore, it must also be recognized that while some publications on herbal medicines may not meet the stringent requirements of international peer-reviewed journals, they may still provide potentially useful observations and ideas for further study. Therefore, a thorough literature survey should be the starting point for every serious effort in herbal medicine research.