Following the disastrous experience with thalidomide women were largely excluded from clinical trials. A change in this paradigm can be observed most recently. For the pharmacokinetics and -dynamics of drugs a body of evidence does exist to prove the presence of significant sex-related differences. Especially fort he major drug metabolizing enzymes, the cytochrome P 450 family, but also for phase II reactions such as glucuronidation, sex-differences were observed. However, most of these differences are either clinically not relevant or were not just observed, because they result in slight increases in the frequency of adverse reactions. Major sex-specific differences were observed for the cardiac elektrophysiology, for opiate and benzodiazepine receptors. Women are significantly more likely to experience drug-induced QT-prolongation and torsade-de-pointes arrhythmia. It should also be considered that conditions such as depression, myocardial infarction and heart failure are characterized by gender-specific symptoms and therefore may deserve a gender-specific therapy. Different trials and epidemiological surveys have repeatedly shown that women experience more adverse drug effects than men.