1. The applications of plant physiology to medical problems.
2. The study of major constituents (active ingredients) and medicinal values of plants; toxicity or hazardous components; essential oils; value-added products and possible uses; cultivation and harvesting; diseases and insects found in medicinal plants.
3. The study of the active chemicals in plants that effect our biological systems. The plants' chemical components are studied for medical and psychoactive reactions.

Many of the chemicals of plants mimic our own bodily chemicals and in some instances enhance the normal reactions that would occur; however, sometimes they block the normal functions of our neural and other cellular functions. These are factors that must be evaluated in the phytopharmacological research of plants.