Psychedelic drugPsychedelics are a subclass of hallucinogenic drugs whose primary effect is to trigger non-ordinary mental states (known as psychedelic experiences or psychedelic "trips") and/or an apparent expansion of consciousness. Sometimes, they are called classic hallucinogens, serotonergic hallucinogens, or serotonergic psychedelics, and the term psychedelic is sometimes used more broadly to include various types of hallucinogens or those which are atypical or adjacent to psychedelia such as salvia and MDMA, respectively; this article uses the narrower definition of psychedelics.
PharmacologyPharmacology is a branch of medicine, biology, and pharmaceutical sciences concerned with drug or medication action, where a drug may be defined as any artificial, natural, or endogenous (from within the body) molecule which exerts a biochemical or physiological effect on the cell, tissue, organ, or organism (sometimes the word pharmacon is used as a term to encompass these endogenous and exogenous bioactive species). It is the science of drugs including their origin, composition, pharmacokinetics, therapeutic use, and toxicology.