Pharmacology may be a branch of drugs and pharmaceutical sciences which cares with the study of drug or medication action, Where a drug are often broadly or narrowly defined as any man-made, 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 employed as a term to encompass these endogenous and exogenous bioactive species). More specifically, it's the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function. If substances have medicinal properties, they're considered pharmaceuticals.