Essiac/Flor Essence (PDQ®): Complementary and alternative medicine - Health Professional Information [NCI] - General Information
Essiac and Flor Essence are proprietary herbal tea mixtures produced by different manufacturers. Essiac is reported to contain four herbs: burdock root (Arctium lappa L.), Indian rhubarb root (Rheum palmatum L., sometimes known as Turkish rhubarb), sheep sorrel (Rumex acetosella L.), and the inner bark of slippery elm (Ulmus fulva Michx. [synonym Ulmus rubra]). Reviewed in [2,3,4,5,6,7,8,9,10] Flor Essence is reported to contain the same four herbs as Essiac, plus four potentiating herbs: watercress (Nasturtium officinale R.Br.), blessed thistle (Cnicus benedictus L.), red clover (Trifolium pratense L.), and kelp (Laminaria digitata [Hudson] Lamx.). Reviewed in [2,3,4,7]
The manufacturers of Essiac and Flor Essence both claim they market the original herbal mixture promoted by the developer.[1,11] Although only one company manufactures Flor Essence, several companies produce and market Essiac-like products. Reviewed in [2,3,10] This summary contains information about the trademarked mixtures only and differentiates between the two products wherever possible. Essiac and Flor Essence may vary in their mixture content and effects.
It is possible that the main title of the report Chronic Myelogenous Leukemia is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.
Essiac and Flor Essence are said to detoxify the body and strengthen the immune system.[1,11] Reviewed in [4,6,7,9] Proponents of Essiac further claim that it helps relieve pain, improves overall quality of life, may reduce tumor size, and may prolong the survival of patients with various types of cancer. Reviewed in [4,7,9] The individual herbs in the Essiac and Flor Essence formulas have been shown to contain molecules that have anticancer, anti-inflammatory, antioxidant, or immunostimulatory activity (refer to the Laboratory/Animal/Preclinical Studies section of this summary for more information). Reviewed in [2,3,4,9,13,14,15,16] It is said that the benefits of Essiac and Flor Essence are dependent on the presence of the constituent herbs in the correct proportions. Reviewed in [2,3,4,9] In 2004, a mixture of the Essiac herbs showed a decreased proliferation of a prostate cancer cell line. (Refer to the Laboratory/Animal/Preclinical Studies section of this summary for more 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).