Women are the principal recipients and have been shown to be the major consumers of drugs. This chapter presents an overview of psychopharmacologic issues relevant to women. It first considers the evidence for sex-related influences on drug disposition, absorption, distribution, and metabolism from studies in humans. It then provides an overview of drug safety during pregnancy and breast-feeding. The chapter lists the most commonly reported malformations attributed to psychotropic drugs taken during the first trimester. It also discusses the information from studies that have examined gender differences in treatment response to antidepressant and antipsychotic drugs. Basic science research has shown that estrogens modulate several of the neurotransmitter systems implicated in psychiatric disorders: they down-regulate beta-adrenergic and serotonin receptors, they have cholinergic trophic effects and they show dopamine antagonist activity. The chapter concludes with a brief summary of some of the studies describing age effects on pharmacokinetics.