Current concepts on integrative safety assessment of active substances of botanical, mineral or chemical origin in homeopathic medicinal products within the European regulatory framework

For active substances of botanical, mineral or chemical origin processed in homeopathic medicinal products for human use, the adequate safety principles as with other human medicinal products are applied in line with the European regulatory framework. In homeopathy, nonclinical safety assessment is facing a particular challenge because of a multitude and diversity of source materials used and due to rarely available toxicological data. Thus, current concepts applied by the national regulatory authority in Germany (BfArM) on integrative safety assessment of raw materials used in homeopathic medicinal products involve several evaluation approaches like the use of the Lowest Human Recommended Dose (LHRD), toxicological limit values, Threshold of Toxicological Concern (TTC), data from food regulation or the consideration of unavoidable environmental or dietary background exposure. This publication is intended to further develop and clarify the practical use of these assessment routes by exemplary application on selected homeopathic preparations. In conclusion, the different approaches are considered a very useful scientific and simultaneously pragmatic procedure in differentiated risk assessment of homeopathic medicinal products. Overall, this paper aims to increase the visibility of the safety issues in homeopathy and to stimulate scientific discussion of worldwide existing regulatory concepts on homeopathic medicinal products.