First, do no harm. It is medicine’s most foundational principle. Yet for decades, a four letter acronym has been quietly violating it-not through malice, but misdirection. Polycystic ovary syndrome (PCOS) told clinicians, researchers, funders, and patients the wrong story. And patients paid the price.This month, that changed. PCOS is now PMOS-polyendocrine metabolic ovarian syndrome-after the most comprehensive medical renaming process ever undertaken: 14 years of global collaboration, 22 000 survey responses, 56 organisations, and 97% consensus.1 Patients were integral from the beginning: instigating action, shaping governance, co-designing surveys, co-chairing workshops, and interpreting and disseminating outcomes alongside health professionals. We listened, challenged and reframed together. I was on stage representing those affected at the European Congress of Endocrinology when we announced this change alongside Helena Teede, Terhi Piltonen, Aled Rees, and Stephen Franks, all experts in the field.PMOS is the most common endocrine disorder worldwide affecting women-with 1 in 8 (more…