Homeopathy (also spelled homoeopathy or homœopathy) is a form of alternative medicine, first proposed by German physician Samuel Hahnemann in 1796, that attempts to treat patients with heavily diluted preparations. Based on an ipse dixit, formulated by Hahnemann which he called the “law of similars”, preparations which cause certain symptoms in healthy individuals are given as the treatment for patients exhibiting similar symptoms. Homeopathic remedies are prepared by serial dilution with shaking by forceful striking, which homeopaths term “succussion,” after each dilution under the assumption that this increases the effect of the treatment. Homeopaths call this process “potentization”. Dilution often continues until none of the original substance remains.
Apart from the symptoms of the disease, homeopaths use aspects of the patient’s physical and psychological state in recommending remedies.[Homeopathic reference books known as repertories are then consulted, and a remedy is selected based on the totality of symptoms. Homeopathic remedies are, with rare exceptions, considered safe though homeopathy has been criticized for putting patients at risk due to advice against conventional medicine such as vaccinations, anti-malarial drugs and antibiotics.
Claims of homeopathy’s efficacy beyond the placebo effect are unsupported by the collective weight of scientific and clinical evidence.While some individual studies have positive results, systematic reviews of published trials fail to conclusively demonstrate efficacy. Furthermore, higher quality trials tend to report less positive results, and most positive studies have not been replicated or show methodological problems that prevent them from being considered unambiguous evidence of homeopathy’s efficacy. A 2010 inquiry into the evidence base for homeopathy conducted by the United Kingdom’s House of Commons Science and Technology Committee concluded that homeopathy is no more effective than placebo.
Depending on the dilution, homeopathic remedies may not contain any pharmacologically active molecules, and for such remedies to have pharmacological effect would violate fundamental principles of science. Modern homeopaths have proposed that water has a memory that allows homeopathic preparations to work without any of the original substance; however, there are no verified observations nor scientifically plausible physical mechanisms for such a phenomenon. The lack of convincing scientific evidence supporting homeopathy’s efficacy and its use of remedies lacking active ingredients have caused homeopathy to be described as pseudoscience, quackery, and a "cruel deception”.
The regulation and prevalence of homeopathy is highly variable from country to country. There are no specific legal regulations concerning its use in some countries, while in others, licenses or degrees in conventional medicine from accredited universities are required. Some homeopathic treatment is covered by the national insurance coverage of several countries; in others it is fully integrated into the national health care system. In many countries, the laws that govern the regulation and testing of conventional drugs do not apply to homeopathic remedies.
A homeopathic remedy prepared from marsh Labrador tea. The “15C” dilution shown here contains no molecules of the original herb.
Homeopathy is a vitalist philosophy in that it interprets diseases and sickness as caused by disturbances in a hypothetical vital force or life force. It sees these disturbances as manifesting themselves as unique symptoms. Homeopathy maintains that the vital force has the ability to react and adapt to internal and external causes, which homeopaths refer to as the “law of susceptibility”. The law of susceptibility implies that a negative state of mind can attract hypothetical disease entities called “miasms” to invade the body and produce symptoms of diseases. However, Hahnemann rejected the notion of a disease as a separate thing or invading entity and insisted that it was always part of the “living whole”.