Alternative medicine, fringe medicine, or pseudo medicine is the use and promotion of practices which are disproven, unproven, impossible to prove, or excessively harmful in relation to their effect, in the attempt to achieve the healing effects of medicine. The scientific consensus is that alternative therapies either do not, or cannot, work. In some cases laws of nature are violated by their basic claims; in some the treatment is so much worse that its use is unethical. Alternative practices, products, and therapies range from ineffective to having known harmful and toxic effects.
Alternative therapies may be credited for perceived improvement through placebo effects, decreased used of medical treatment (and therefore potentially decreased side effects), regression toward the mean, or the natural course of the condition or disease. Alternative treatment is not the same as experimental treatment or traditional medicine, although both can be misused in ways that are alternative. Alternative medicine is used by a significant number of people, though its popularity is often overstated. Large amounts of funding go to testing alternative medicine, with more than US$2.5 billion spent by the United States government alone. Almost none show any effect beyond that of false treatment, and most studies showing any effect have been statistical flukes. Regulation and licensing of alternative medicine and health care providers varies between and within countries.