Review of the use of high potencies in basic research on homeopathy.

The HomBRex database includes details of about 1500 basic research experiments in homeopathy. A general overview on the experiments listed in the HomBRex database is presented, focusing on high dilutions and the different settings in which those were used. Though often criticised, many experiments with remedies diluted beyond Avogadro's number demonstrate specific effects. A total of 830 experiments employing high potencies was found; in 745 experiments of these (90%), at least one positive result was reported. Animals represent the most often used model system (n=371), followed by plants (n=201), human material (n=92), bacteria and viruses (n=37) and fungi (n=32). Arsenicum album (Ars.) is the substance most often applied (n=101), followed by Sulphur (Sulph.) and Thuja (Thuj.) (n=65 and 48, respectively). Proving, prophylactic and therapeutic study designs have all been used and appear appropriate for homeopathy basic research using high dilutions. The basic research data set to support specific effects unique to high dilutions and opposite to those observed with low dilutions is, to date, insufficient.