Pharmacogenomics is the study of how an individual's genetic profile affects their response to medications. It aims to provide the right drug at the right dose for the right patient by understanding genetic factors. Current applications include testing for genetic variants before prescribing certain drugs to avoid bad reactions. Challenges include accounting for both genetic and environmental influences on drug responses and protecting patient privacy. As understanding and technologies improve, pharmacogenomics may help develop new drugs and reduce trial-and-error prescribing.