Basic science research in homeopathy has been conducted in two main areas:
(1) in-vitro or in-vivo biological models of the action of ultra-molecular dilutions and their potential mechanisms of action, including the similia principle (the concept of treating like with like);
(2) physical research on ultra-molecular dilutions.
The Homeopathy Basic Research Experiments (‘HomBRex’) Database, a comprehensive database of basic research in homeopathy, contains information on experiments on biological systems in-vivo and in-vitro, in healthy or diseased states, ranging from the intact organism to the subcellular level, with measures of effect ranging from viability to molecular processes; and research on physico-chemical effects of serially agitated homeopathic preparations.
About 100 researchers from different universities and institutes in Europe are working in this domain and are members of the GIRI = Groupe Internationale de Recherches Infinitisimales = International group of researchers studying the effects of serially agitated high dilutions.