Herbal medicine is the oldest continuously practiced form of health care on the planet. The World Health Organization (WHO) indicates that over 80% of the world's population still relies upon local medicinal plants as a primary form of health care. Even today, modern medicine derives 30% of its pharmaceuticals from herbal remedies, such as the heart drug digoxin (a glycoside from Foxglove [Digitalis purpurea]), the sinus decongestant pseudoephedrine (an alkaloid from the Chinese herb Ma Huang [Ephedra sinica]), and the cancer drug vincristine (an alkaloid from the Madasgascar Perrywinkle [Catharanthus roseus]).

Although modern medicine reduces herbal medicines to their chemical constituents, the practice of herbal medicine is founded upon the concept of 'wholism', an idea which suggests that each unit of living matter or reality is made up of unified wholes that are greater than the sum of its parts. This view of the body is especially important in the treatment of illness for it recognizes the myriad number of factors that can influence the health of the body, including diet, lifestyle, genetics, the environment, emotions and thoughts, and spirituality.

Humans have been using plants as medicine for so long that our bodies are well-adapted to their familiar chemical profiles, and as a result, most plant-based remedies are well tolerated, free of the striking adverse effects that compromise the benefits of many pharmaceuticals. The often diverse array of phytochemicals in many plants affords further benefit, with many of these compounds working together in a synergistic fashion to correct some wrong of the body.