Homeopathy is a medical system which uses homeopathic preparations (praeparationes homeopathicae according to the European Pharmacopoeia) to treat patients. This therapeutic modality aims at identifying a specific remedy for each individual patient that fits as closely as possible the totality of symptoms experienced by that patient. An appropriate homeopathic remedy is chosen based on the best possible match of a patient's symptoms and the symptoms a preparation is able to induce in healthy volunteers (similia similibus curentur, the so-called simile principle, “let like be cured by like”). Consequently, homeopathic therapy relies on an exhaustive collection of symptoms caused by different substances in healthy persons (materia medica), based on toxicological investigations and so-called drug provings which assess the effects of homeopathic preparations in healthy volunteers. In therapy, substances are applied in potentized form (potentization principle) which means that a given substance is repeatedly diluted and succussed (shaken vigorously). The final dilution factor may exceed the inverse Avogadro number which leads to a very low probability of molecules of the potentized substance still being present in the potentized form. It is therefore sometimes argued that application of the potentization principle leads to preparations identical to placebo, concluding that homeopathic therapy is nothing but a placebo treatment.
Nevertheless, homeopathy is one of the most sought-after complementary therapies in Switzerland, and also very popular in many countries across Europe and all over the world. Production of homeopathic preparations is regulated in many pharmacopoeias, including the European, US, Brazilian and Indian pharmacopoeias .
The basic principles of homeopathy were developed by Smuel Hahnemann1 (1755–1843) and described in several textbooks2,3.