
Homeopathy (also homœopathy or homoeopathy; from the Greek ὅμοιος, hómoios, "similar" + πάθος, páthos, "suffering" or "disease") is a popular alternative medicine that is controversial because of its lack of scientific plausibility and confirmation. Homeopaths contend that remedies for diseases can be created by taking substances which cause symptoms similar to that disease and repeatedly diluting and shaking them between each dilution. According to homeopaths the 'therapeutic powers' of the substance are retained by the diluent (water, sugar, or alcohol), but the dilution removes any negative effects. The end product is usually so diluted that it is indistinguishable from pure water, sugar or alcohol by laboratory tests but is still claimed to have an effect on consumers.Homeopathy was created by Samuel Hahnemann in the late 18th century. The therapeutic applications of the remedies used in homeopathy are recorded in homeopathic materia medica, and practitioners select treatments according to a patient consultation that explores both the physical and psychological state of the patient. Homeopathic remedies are generally not tested and regulated under the same laws as conventional drugs, and usage varies from only two percent of people in Britain and the United States using homeopathy in any one year, to 15 percent in India, where homeopathy is now considered part of its traditional medicine.The ideas behind homeopathy are scientifically implausible and "diametrically opposed to modern pharmaceutical knowledge". Claims for its efficacy beyond the placebo effect are unsupported by the collective weight of scientific and clinical studies. The lack of convincing scientific evidence supporting its efficacy, and its contradiction of basic scientific principles, have caused homeopathy to be regarded as pseudoscience, or, in the words of a recent medical review, as "placebo therapy at best and quackery at worst". Homeopathic remedies are generally considered safe, with rare exceptions; however, homeopaths have been criticised for putting patients at risk by advising them to avoid conventional medical treatments such as vaccinations, anti-malarial drugs and even antibiotics.