An antifibrinolytic agent, tranexamic acid (commonly used to reduce bleeding during surgery) is being investigated as first-aid to cut mortality and the need for blood transfusion immediately after trauma or injury. The CRASH trial, still in its early phases in a worldwide adult population, aims to bring particular benefit to developing countries, many of which are blighted by trauma with few measures, if any, having been available up to now to reduce the death toll. In Lima, Peru, Jaime Miranda discussed his group’s ongoing investigation with Peter Goodwin.