Most medicines work by binding to and modifying the actions of proteins, tiny molecular machines that perform important cellular tasks. Details about protein structure and function help scientists develop medicines that block proteins or otherwise interact with them. But even when a drug is designed to target a specific protein, it can sometimes impact others, causing side effects. The way medicines work also can be influenced by how a person's body absorbs and processes them.
Findings from research funded by the National Institutes of Health have shed light on how some common medicines work.