Wikipedia
Oscillococcinum (or Oscillo) is a homeopathic preparation marketed to relieve influenza-like symptoms. It is a popular preparation, particularly in France. It is manufactured by Boiron, its sole manufacturer. Oscillococcinum is used in more than 50 countries and has been in production for over 65 years.
The preparation is derived from duck liver and heart, diluted to 200 C—a ratio of one part duck offal to 10 parts water. Homeopaths claim that the molecules leave an " imprint" in the dilution that causes a healing effect on the body, although there is no evidence that supports this mechanism or efficacy beyond placebo.
Oscillococcinum was originally proposed by the French physician Joseph Roy, based on his misidentification of an oscillating bacterium he named oscillococcus in victims of the Spanish flu epidemic of 1917-1918. Roy said he had seen the same bacterium in cancer sufferers, and proposed a homeopathic preparation (which he claimed to have isolated in a duck) as a remedy for the Spanish flu. The microbes Roy said he saw have never been independently observed by any other researcher.