The contribution of health care to environmental and climate crises is significant, under-addressed, and with consequences for human health. This editorial is a call to action. Focusing on pharmaceuticals as a major environmental threat, we examine pharmaceutical impacts across their lifecycle, summarising greenhouse gas emissions, pollution, and biodiversity loss, and outlining challenges and opportunities to reduce this impact. We urge health care decision-makers and providers to urgently consider environmental factors in their decision-making relating to both policy, and practice, promoting actions such as rational prescribing, non-pharmaceutical interventions, and research and advocacy for sustainable production, procurement, and use.