<unk>  is an alternative medical treatment that introduces<unk>  or<unk> des to the body. In April 2003, the United States Food and Drug Administration (FDA) prohibited all medical uses of<unk> , "In any medical condition for which there is no proof of safety and effectiveness", stating<unk>  is a toxic gas with no known useful medical application in specific, adjunctive, or preventive therapy. In order for<unk>  to be effective as a germicide, it must be present in a concentration far greater than that which can be safely tolerated by man and animals."<unk>  has been sold as an unproven treatment for various illnesses, including cancer, a practice which has been characterized as "pure quackery". The therapy can cause serious adverse effects, including death.
Ozone therapy
Maggot therapy
Ultraviolet light therapy
Narrative exposure therapy
Topical steroid withdrawal
Particle therapy
Allergen immunotherapy
Asthma spacer