Herbal medicine is the oldest and still the most widely used system of medicine in the world today. It is medicine made exclusively from plants. It is used in all societies and is common to all cultures.
There are many different "types" of herbal medicine that spring from different cultures around the world. All these have the use of medicinal plants in common, but they vary in the plants they use, the way they prepare and use medicines from these plants, and the philosophy of their treatment approaches. Different cultures may also use the same plants but differ in how it is used, or the part they use.
Herbal medicine is increasingly being validated by scientific investigation which seeks to understand the active chemistry of the plant. Many modern pharmaceuticals have been modeled on, or derived from chemicals found in plants. An example is the heart medication digoxin derived from foxglove (Digitalis purpurea).
Using plants as medicine provides significant advantages for treating many conditions. The therapeutic activity of a plant is due to its complex chemical nature with different parts of the plant providing certain therapeutic effects.