The Three Rs framework - Replace, Reduce, Refine - guides efforts to minimize animal use and suffering in biomedical research while maintaining scientific progress.
The Three Rs framework has driven meaningful improvements in research animal welfare over six decades, but significant welfare challenges remain in research settings. The shift toward replacement methods has accelerated dramatically with advances in organoids, organ-on-chip technology, and computer modeling that can replicate biological processes without animals. Reduction through improved statistical design and data sharing prevents redundant experiments using animals who would otherwise face the same procedures. Refinement encompasses everything from improved analgesia and anesthesia protocols to better housing conditions and humane endpoints that end experiments before maximum suffering is reached. Despite progress, millions of animals experience significant pain, distress, and suffering annually in research settings, and continued investment in replacement methods represents the most impactful long-term pathway to improving research animal welfare.