Drugs of natural origin continue to be important for the treatment of many diseases worldwide. Pharmacognosy, a long-established pharmaceutical science, has played a diverse role in the discovery, characterisation, production and standardisation of these drugs. The relevance of this discipline in terms of research and teaching has increased in the last decade as members of the public in developed countries have turned to the use of herbal remedies for the self-medication of minor diseases. However, many phytomedicines require further investigation for their clinical effectiveness, while others need to be thoroughly investigated for their potential health risks or interactions with prescription drugs.