Essiac
Essiac is a herbal tea promoted as an alternative treatment for cancer and other illnesses. There is no evidence it is beneficial to health. In a number of studies Essiac either showed no action against cancer cells, or actually increased the rate of cancer growth.
Background
While the formulations can vary, most Essiac formulations contain burdock root, turkey rhubarb root, sheep sorrel and slippery elm. From the 1920s through the 1970s, Essiac was promoted as a cancer treatment by Rene Caisse, a Canadian nurse who invented the formula. Caisse claimed at some times that the formula had been given to her by an Ontario Ojibwa patient she treated, and at other times that she had learned the formula from an unnamed "medicine man". Neither story has ever been substantiated. There is no evidence that Essiac is a Native American or First Nations remedy. However, there are multiple factors that indicate the formula is not from any Native American or First Nations culture. Notably, in the original recipe, only one of the plants in the mixture, slippery elm, is indigenous to the Americas; none of the other herbs are native to North America. Caisse changed her story about the origins of the remedy, as well as the ingredients in the formula, several times, and was said to be fond of cultivating "an air of mystery" around it. The name "Essiac", which Caisse gave to the tea, is Caisse's name spelled backwards. Today, Essiac is often sold with apparatus for making the tea, and is sometimes promoted with untrue claims that scientific studies have shown it to be effective.In 1977, Caisse sold her Essiac formula and trademark rights to Respirin Corporation, which attempted to commercialize the product. However, the company was unable to show any efficacy of Essiac against cancer. Repeated laboratory tests showed that Essiac failed to slow tumor growth and, in large doses, killed test animals. In a number of studies, Essiac actually increased the rate of cancer growth. As a result, both the U.S. and Canadian governments refused to approve Essiac as a medical treatment. Essiac was instead marketed by Essiac Products Inc. and others as a dietary supplement, subject to much looser regulation and not required to show any proof of effectiveness.