Herbal complexes are currently considered to be the cornerstones of a branch of phytotherapy. They are groups of various plant components that are thought to have therapeutic effects. Each component has its own role and specific function within a complex life system, and the function of a complex is determined both by those elements that act directly upon it and by those that influence it only indirectly.
A herbal complex is therefore normally a mixture of derivatives (drugs or extracts) from different plants. Systemic study of their main natural active components, in order to create new opportunities for intervention, requires deep knowledge of many subjects in the field of health science: it is necessary to be very familiar with ethnobotany, chemistry, and pharmacology.
Normally, the study of a certain plant and its properties is based on knowledge derived from popular medicine. However, scientific research confirming these uses is impeded by the fact that isolating the main active ingredient, regardless of whether it is an alkaloid or glycoside, does not guarantee that all of the effects the extract could generate will be found, since it is frequently the entire phytochemical spectrum of the plant that produces the effect.
The main active ingredients that make up herbal compounds can be extracted from various parts of the chosen plants. Generally, the metabolites come from roots, rhizomes (underground stems), tubers (organs that are not visible), bulbs (spherical structures formed from stems and squamae or leaves), bark (the outermost part of the trunk), wood, grasses, flowering tips, leaves, flowers, fruits, cuts (undifferentiated plant components), and seeds.