Future developments in pharmaceutical research, regulatory requirements such as the EU Cosmetics Directive, and the european REACH program on registration, evaluation, au-thorisation and restrictions of chemicals require high numbers of animal experiments. As a result of ethic concerns, cell culture tests are considered as a potential alternative. However, current testing protocols using 2D cell cultures in Petri dishes are not equivalent to animal trials. Therefore, characterized human micro-organoids representing a broad range of genetic diversity could be advantageous. By now, there is increasing interest among industrial companies for human micro-organoids as test systems for the REACH program. New in vitro test systems such as bioreactor based 3D tissue cultures (so called micro organoids) hold an enormous potential for the replacement of animal trials. It is anticipated that these culture systems will allow for solutions in many problems related to pharmaceutical testing.