Scientific proving of ultra high dilutions on humans

Homeopathic drug provings or pathogenetic trials (HPTs) are the pillar of homeopathy. This review summarizes the authors' findings and interpretations derived from a series of homeopathic drug proving between 1994 and 2015. It gives an overview over a series of attempts to use modern scientific experimental methodology to answer the question, whether such HPTs produce symptoms in healthy volunteers that can be distinguished from placebo symptoms.

Various experimental models were used: repeated crossover trials with categorical data collection, and a single-case, randomised study. Final models use diligent qualitative data-collection in experienced volunteers. In those, raters decide whether symptoms are typical for a remedy delivered or not. The design is triple-blind and placebo-controlled.

While previous attempts were inconclusive, this new model allowed to separate placebo symptoms from verum symptoms repeatedly in a series of two definitive studies following promising pilot studies. Results were statistically significant. Also, some signs of the purported non-local signature of homeopathic effects were visible, and the consequences for future methodology is discussed.

Provided some cautionary notes are taken into account, HPTs can be used to separate out true specific symptoms from placebo symptoms. By the same token this is a road to experimental proof that homeopathic remedies are not just placebos. However, this needs to be taken forward by independent groups.