• Essiac and Flor•Essence are herbal tea mixtures that are sold worldwide as health tonics or herbal dietary supplements (see Question 1 ¹).



• Essiac was first promoted as a cancer treatment in the 1920s. Flor•Essence was created a number of years later (see Question 2 ²).



• Supporters of Essiac and Flor•Essence say that these products make the immune system stronger, have anti-inflammatory effects, and show anticancer activity (see Question 3 ³).



• Laboratory, animal, and clinical (human) studies with Essiac and Flor•Essence have not reported clear evidence of an anticancer effect (see Question 5 ⁴ and Question 6 ⁵).



• The U.S. Food and Drug Administration has not approved Essiac or Flor•Essence as a cancer treatment (see Question 8 ⁶).

Glossary Terms

A laboratory experiment using animals to study the development and progression of diseases. Animal studies also test how safe and effective new treatments are before they are tested in people.

Having to do with reducing inflammation.

A term for diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissues and can spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord.

A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening, prevention, diagnosis, or treatment of a disease. Also called clinical trial.

A product that is added to the diet. A dietary supplement is taken by mouth, and usually contains one or more dietary ingredient (such as vitamin, mineral, herb, amino acid, and enzyme). Also called nutritional supplement.

An herbal tea mixture that contains burdock root, Indian rhubarb root, sheep sorrel, and slippery elm bark. It has been claimed to remove toxins from the body, make the immune system stronger, relieve pain, control diabetes, treat AIDS, reduce tumor size, increase cancer survival, and improve quality of life. No clinical trial using Essiac in humans has been reported in a peer-reviewed, scientific journal, and the FDA has not approved the use of Essiac for the treatment of any medical conditions.

An agency in the U.S. federal government whose mission is to protect public health by making sure that food, cosmetics, and nutritional supplements are safe to use and truthfully labeled. The Food and Drug Administration also makes sure that drugs, medical devices, and equipment are safe and effective, and that blood for transfusions and transplant tissue are safe. Also called FDA.

Having to do with plants.

The complex group of organs and cells that defends the body against infections and other diseases.

Research done in a laboratory. These studies may use test tubes or animals to find out if a drug, procedure, or treatment is likely to be useful. Laboratory studies take place before any testing is done in humans.