Pharmacology is the scientific field that studies how the body reacts to medicines and how medicines affect the body. Scientists funded by the National Institutes of Health are interested in many aspects of pharmacology, including one called pharmacokinetics, which deals with understanding the entire cycle of a medicine’s life inside the body. Knowing more about each of the four main stages of pharmacokinetics—absorption, distribution, metabolism and excretion—aids the design of medicines that are more effective and that produce fewer side effects. Read more about a medicine’s life inside the body in this Inside Life Science article.