The Food and Drug Administration (FDA) is taking two important steps to ensure that new drugs are properly evaluated in women. First, it is providing formal guidance to drug developers to emphasize its expectations that women will be appropriately represented in clinical studies and that new drug applications will include analyses capable of identifying potential differences in drug actions or efficacy between the sexes. Second, the agency is altering a 16-year-old policy that has excluded most women with “childbearing potential” from the earliest phases of clinical trials.

Attention to sex differences is part of a larger effort by the FDA . . .