Quacks, the people who promote these products, have been around for years. One of the most enduring images of nineteenth-century medicine is the charlatan or quack. These individuals sold primarily patent medicines that promised to cure everything from cancer to the common cold. Patent medicines were concoctions (elixirs, salves, balms, etc.) for which individuals received exclusive rights to sell for a given period of time. Patent medicines were available by mail or over the counter at chemists' shops, general stores, and even seed stores. Most patent medicines contained alcohol, and many also contained opium or morphine. Virtually none contained the "healing" ingredients they claimed to have, and none healed.
Some quacks were called "snake oil" salesmen. These individuals traveled from town to town, sometimes with a carnival, selling their products. Today, quacks have more sophisticated ways to sell their products. The products are now promoted on the Internet, TV, and radio; in magazines, newspapers, and infomercials; by mail; and even by word-of-mouth. Many consider quackery to be a pejorative term and now use the term alternative medicine. However, this term is used in a variety of ways. The physician Stephen Barrett suggests that "alternative" methods be classified as genuine, experimental, or questionable, whereas quackery refers solely to questionable and unproven methods.
Read more: http://www.faqs.org/nutrition/Pre-Sma/Quackery.html#ixzz4EC1Q277X