Herbal medicines include herbs, herbal materials, herbal preparations and finished herbal products. In some countries herbal medicines may contain, by tradition, natural organic or inorganic active ingredients that are not of plant origin (e.g. animal and mineral materials).

Herbs include crude plant material, such as leaves, flowers, fruit, seeds, stems, wood, bark, roots, rhizomes or other plant parts, which may be entire, fragmented or powdered.

Herbal materials include, in addition to herbs, fresh juices, gums, fixed oils, essential oils, resins and dry powders of herbs. In some countries, these materials may be processed by various local procedures, such as steaming, roasting or stir-baking with honey, alcoholic beverages or other materials.

Herbal preparations are the basis for finished herbal products and may include comminuted or powdered herbal materials, or extracts, tinctures and fatty oils of herbal materials. They are produced by extraction, fractionation, purification, concentration, or other physical or biological processes. They also include preparations made by steeping or heating herbal materials in alcoholic beverages and/or honey, or in other materials.

Finished herbal products consist of herbal preparations made from one or more herbs. If more than one herb is used, the term “mixture herbal product” can also be used. Finished herbal products and mixture herbal products may contain excipients in addition to the active ingredients. However, finished products or mixture herbal products to which chemically defined active substances have been added, including synthetic compounds and/or isolated constituents from herbal materials, are not considered to be herbal.

Traditional use of herbal medicines refers to the long historical use of these medicines. Their use is well established and widely acknowledged to be safe and effective, and may be accepted by national authorities.

Therapeutic activity refers to the successful prevention, diagnosis and treatment of physical and mental illnesses. Treatment includes beneficial alteration or regulation of the physical and mental status of the body and development of a sense of general well-being as well as improvement of symptoms.

Active ingredients refer to ingredients of herbal medicines with therapeutic activity. Where the active ingredients have been identified, the preparation of the finished herbal product should be standardized to ensure that it always contains a defined amount of the active ingredients, providing adequate analytical methods are available. In cases where it is not possible to identify the active ingredients, the whole herbal medicine may be considered as one active ingredient.

Traditional medicine is the sum total of the knowledge, skills and practices based on the theories, beliefs and experiences indigenous to different cultures, whether explicable or not, used in the maintenance of health and in the prevention, diagnosis, improvement or treatment of physical and mental illness. The terms “complementary medicine”, “alternative medicine” and “nonconventional medicine” are used interchangeably with “traditional medicine” in some countries.

Terms relating to safety monitoring of medicinal products The terms and definitions below have been adopted by the national pharmacovigilance centres participating in the WHO International Drug Monitoring Programme. Different medical paradigms may view clinical events differently in their relationship to herbal medicines, whether they are expected therapeutic outcomes or adverse reactions.

Side effect. Any unintended effect of a pharmaceutical product occurring at doses normally used in humans that is related to the pharmacological properties of the drug. Adverse event/experience. Any untoward medical occurrence that may present during treatment with a pharmaceutical product but that does not necessarily have a causal relationship with this treatment.

Serious adverse event. Any untoward medical occurrence that, at any dose:

• results in death
• requires inpatient hospitalization or prolongation of existing hospitalization
• results in persistent or significant disability/incapacity
• is life-threatening

Adverse reaction. A response to a drug that is noxious and unintended, and that occurs at doses normally used in humans for the prophylaxis, diagnosis or therapy of disease, or for the modification of physiological function.

Unexpected adverse reaction. An adverse reaction, the nature or severity of which is not consistent with domestic labeling or market authorization, or expected from the characteristics of the drug.

Signal. Reported information on a possible causal relationship between an adverse event and a drug, the relationship being unknown or incompletely documented previously. Usually, more than a single report is required to generate a signal, depending upon the seriousness of the event and the quality of the information.

Spontaneous reporting. A system whereby case reports of adverse drug events are voluntarily submitted by health professionals and pharmaceutical manufacturers to the national regulatory authority.

Pharmacovigilance is the science and activities relating to the detection, assessment, understanding and prevention of adverse effects or any other possible drug-related problems.

National pharmacovigilance centre. A single, governmentally recognized centre (or part of an integrated system) within a country with the clinical and scientific expertise to collect, collate, analyze and give advice on all information related to drug safety.