Herbal medicine, also called botanical medicine or phytomedicine, is the practice of using one or more parts of a plant — its seeds, berries, roots, leaves, bark, or flowers — to relieve physical and psychological problems, prevent disease, or just improve overall health and vitality. Although many modern drugs were originally developed from plants, they are based on isolated chemicals, while plants comprise myriad active components, which work together to create their medicinal actions. Herbs have a long history of use and, when used properly, are safe and powerful medicines.