Essiac/Flor Essence (PDQ®): Complementary and alternative medicine - Health Professional Information [NCI] - General Information
Although the use of Essiac and Flor Essence is generally associated with cancer treatment, both products have been used to treat other health conditions. Essiac has reportedly been used to control diabetes and to treat acquired immunodeficiency syndrome. Reviewed in  Flor Essence has reportedly been studied in Russia as a treatment for chronic gastrointestinal diseases (e.g., esophagitis, gastritis, duodenitis, and colitis) and as a treatment for cirrhosis of the liver. Reviewed in  However, no controlled data have been published in the peer-reviewed scientific literature to show the safety or the efficacy of Essiac or Flor Essence in patients with cancer or in patients with other health conditions (refer to the Human/Clinical Studies section of this summary for more information).
Essiac and Flor Essence are sold worldwide as health tonics or herbal dietary supplements.[1,11] Reviewed in [2,3,4,10] In the United States, health tonics and dietary supplements are regulated as foods, not drugs. Therefore, premarket evaluation and approval by the U.S. Food and Drug Administration (FDA) are not required, and specific disease treatment or prevention claims are not allowed. Because health tonics and dietary supplements are not formally inspected for manufacturing consistency, there may be considerable variation from lot to lot, and there is no guarantee that ingredients identified on product labels are present at all or are present in the specified amounts. The FDA has not approved the use of either Essiac or Flor Essence for the treatment of patients with cancer or any other medical condition.
To conduct clinical drug research in the United States, researchers must file an Investigational New Drug (IND) application with the FDA. An IND application must also be made for clinical evaluation of dietary supplements as agents for the treatment or prevention of disease. The FDA's IND process is confidential, and the existence of an IND application can be disclosed only by the applicants. To date, no investigator has announced filing an IND application to study either Essiac or Flor Essence in the treatment of patients with cancer.