The gender equality and women’s empowerment agenda is recognised in the Sustainable Development Goals (SDGs) and by various UN and government commitments before the SDGs. However, mainstream public health and public policy have yet to invest substantially in research and action to tackle gender inequalities in health. Building on the Women and Gender Equity Knowledge Network (WGEKN) report submitted to the WHO’s Commission on Social Determinants of Health, the new Lancet Series on gender equality, norms, and health brings back to the foreground the urgency with which attention, resources, action, and accountability must be dedicated to transform gender inequalities in health. Gender inequality remains one of the most pervasive inequalities in health and one of the most insidious because it is one where backlash against progress retains legitimacy and actively contests progressive change.