Dr. Samuel Hahnemann developed homeopathy approximately 200 years ago. It is based on the theory of similars and the use of infinitesimal doses. The idea is that a substance that can cause certain symptoms will also cure those symptoms, when administered in an extremely diluted form.
Pharmacopoeias specify the ingredients and detailed procedures for preparation of homeopathic medicines. Because pharmacopoeias are living documents that are updated from time to time by relevant professional and advisory committees, not all active ingredients used in the manufacture of homeopathic medicines sold in Canada are listed in the five pharmacopoeias recognized by Health Canada. Additional ingredients are eligible for inclusion in homeopathic medicines if they comply with monographs published by the Natural Health Products Directorate or are supported by an acceptable body of evidence for efficacy and safety. NHPD's guidance document for homeopathic medicines and monographs can be viewed at http://www.hc-sc.gc.ca/dhp-mps/prodnatur/legislation/docs/ehmg-nprh-eng.php
You can learn more about homeopathy, its practitioners and some of the associated research from the following web sites: