Alternative and complementary methods serve to decrease or eliminate the use of animals and the distress they suffer in experiments. In doing so, these methods must be at least as reliable and representative as conventional experiments. Typical 3Rs methods are
In order to be officially acknowledged as EU and OECD experimental guidelines, alternative and complementary methods must undergo international validation studies proving that their reliablity is sufficient to replace current methods presently required by law.
Over the last twenty years, projects backed by several organizations have made considerable advances in this field: A number of alternative methods that completely forgo experiments on live vertebrates have become legal requirements. Improvements in efficiency have optimised some methods which formerly required large numbers of animals. Based on these developments, legal guidelines for several areas of research have been amended, thereby significantly reducing the number of animals used and their distress.
Besides efforts to devise alternatives to mandatory experiments, research for alternative and complementary methods also covers a multitude of non-mandatory animal experiments.