Historically, the male body was treated as the universal medical baseline, and women of "child-bearing potential" were systematically excluded from early-phase clinical trials, notably after a 1977 FDA mandate. This historical exclusion created a significant knowledge gap regarding how diseases and treatments uniquely affect women.

Drug Metabolism and Adverse Reactions Biological sex significantly alters drug pharmacokinetics—how a drug is absorbed, distributed, metabolized, and excreted. Men and women differ in body composition (such as fat and total water percentages) and liver enzyme activity (such as Cytochrome P450 variants), which drastically affects drug clearance. Because standard dosages were historically optimized for men, women experience adverse drug reactions (ADRs) nearly twice as often as men. A prime example is the sleep med ...