Toward a common interpretation of the 3Rs principles in animal research

The 3Rs Principles of Replacement, Reduction, and Refinement have gained widespread recognition as basic guidelines for animal research. Despite their broad acceptance, there is a conspicuous lack of consensus on what exactly they mean, yet stakeholders keep referring to them while espousing their own implicit interpretations. This variety of interpretations is then transposed into statutory frameworks at various levels, reflecting a diversity of meanings which have both technical and practical impacts. Here, we argue that there should be no room for ambiguity, and that for the 3Rs to serve as guidelines and for their widespread implementation, the scientific community must reach consensus on their meaning. Thus, we offer a common interpretation agreed on by the members of the EU-funded Cost Action IMPROVE – a network dedicated to “using the 3Rs concepts to improve the quality of biomedical science”– listed in Table 1.