Ethical and animal-welfare concerns have long fuelled efforts to curb animal use in research — and now rapid advances in alternative scientific methods are accelerating the shift. These ‘new approach methodologies’ (NAMs) include devices known as organs-on-chips, 3D tissue cultures called organoids and computational models, such as artificial-intelligence systems. The number of biomedical publications using only NAMs grew from around 25,000 to 100,000 between 2006 and 2022, according to an analysis of studies on seven diseases by Animal Free Research UK, an organization that promotes the replacement of animal experiments. And China is investing heavily in this area: in 2024, it launched the Human Organ Physiopathology Emulation System, an infrastructure project dedicated to developing NAMs, backed with an investment of 2,640 million yuan (US$382 million).