In the 1920s, Canadian naturopathic nurse Rene Caisse developed the formula for Essiac tea. This four-herb blend, which included burdock root, sheep sorrel, slippery elm bark, and turkish rhubarb, became one of the world's most popular naturopathic treatments for cancer. Later, herbalists added herbs like blessed thistle, red clover, kelp, and watercress to Caisse's original formula, and the resulting product was re-marketed under the name Flor-Essence. As of 2010, there is little scientific evidence to suppor the use of Flor-Essence as a treatment for any disease. Nevertheless, the product's advocates claim that it offers several valuable heath benefits.
Cancer Treatment
According to the National Institutes of Health, Flor-Essence and related products have been used to treat virtually every form of cancer. In 2000, nearly 15% of Canadian women with breast cancer used Flor-Essence or Essiac tea. However, the American Cancer Society warns that there is not enough evidence to support the use of Flor-Essence to treat any type of cancer. In fact, it may paradoxically increase the growth of hormone-sensitive breast cancers.
Pain Relief
According to the American Cancer Society, Flor-Essence advocates claim that the herbal concoction can relieve pain. The constituent herbs used in Flor-Essence may help to relieve underlying causes of pain, including inflammation. Flor-Essence may also help to lubricate joints. The National Institutes of Health note its popularity as a naturopathic treatment for arthritis. There is not enough evidence to support the use of Essiac as a pain reliever.
Detoxification
Herbal cancer treatments are widely promoted as "detoxification" methods. According to the American Cancer Society, some cancer patients believe that Flor-Essence can flush excess from the organs and protect against environmental toxins. Flor-Essence may have a laxative effect and may be used as a component of colon cleansing. The National Institutes of Health note that this use is based solely in tradition and theory.
Immune Support
Flor-Essence is used to support healthy immune function in people with chronic illnesses as well as people who are generally healthy. According to the National Institutes of Health, some people use Flor-Essence and similar products to boost immune defenses against viral and bacterial infections. Flor-Essence may also be used as a treatment for serious viral infections like HIV and Lyme disease.


