Homeopathy developed about 200 years ago by the German physician Samuel Hahnemann has overtime become one of the most common complementary and alternative medicine procedures performed to treat cancer in the United States and Europe. In this procedure, based on the principle of “like cures like”, substances that have been diluted many times are used to treat patients, who show symptoms that the substances would cause when used in healthy people. Homeopathy is thought to stimulate the body's self-healing ability in this way. The studies carried out up to date have provided no strong evidence supporting the use of homeopathy in any clinical condition. The studies that have given positive results were methodologically incomplete. The procedure is claimed to be harmless, based on the fact that the active ingredients contained in homeopathic products are highly diluted. Sufficiently diluted homeopathic products are harmless as claimed, except for rare and non-serious side effects such as allergic reactions. However, studies reveal that also inadequately diluted products containing high levels of active ingredients are available in the market. Taking into account this danger, it is hard to say that the method is totally harmless.