The basic ambition of personalized medicines is for patients to receive medications, which if not tailored for them as individuals, will be designed more specifically for them as part of a group of genetically, physiologically, or pathologically similar patients. This is in contrast to the current and frequently applied modus, which involves most patients receiving the same drug at the same dose and at the same frequency as others. There are of course exceptions to this. The postgenomic era in which we are purported to live has promised much, but has delivered less. The promise is that through a better understanding of pharmacogenetics and pharmacogenomics and through genetic profiling of patients especially those involved in clinical trials, more valuable data will become available to support the treatment of individuals and groups who are first likely to respond to the medication and/or be unlikely to suffer adverse reactions from its administration.