Non-human primates are used in biomedical research due to their physiological and cognitive similarity to humans. This similarity also makes them among the most welfare-sensitive laboratory species, driving intensive efforts to develop alternatives.
Non-human primates experience welfare harm from confinement in laboratory settings at higher severity than most other laboratory species, due to their high cognitive complexity and social requirements. Research procedures including blood sampling, behavioral testing, and experimental treatments cause stress that cumulates across long research careers. The 3Rs imperative to replace primate research where alternatives exist is urgent; replacement where full replacement is not yet possible requires extensive refinement. The direction of travel — toward primate-free alternatives — is established; the speed of transition depends on research investment and regulatory pressure.