1. What are Essiac and Flor•Essence?

   Essiac and Flor•Essence are herbal tea mixtures that have been used as anticancer treatments. They have been used to treat other health conditions also, including diabetes, AIDS, and gastrointestinal diseases.

   Essiac is reported to contain 4 herbs:

   • Burdock root.
   • Indian rhubarb root.
   • Sheep sorrel.
   • Slippery elm (the inner bark).

   Flor•Essence is reported to contain the same 4 herbs found in Essiac plus these 4 other herbs:

   • Watercress.
   • Blessed thistle.
   • Red clover.
   • Kelp.

   Different batches of these mixtures may contain different ingredients or amounts and the effects may not always be the same.

   Essiac and Flor•Essence are sold worldwide as health tonics or herbal dietary supplements. One company sells Flor•Essence and several companies make and sell mixtures called Essiac. This summary refers to the trademarked (brand name) mixtures only.

2. What is the history of the discovery and use of Essiac and Flor•Essence as complementary or alternative treatments for cancer?

   A nurse in Canada first began to promote Essiac as a cancer treatment in the 1920s. Today, Essiac and Flor•Essence may be sold as herbal supplements as long as they do not claim to treat or cure cancer.

   • In 1922, a breast cancer patient gave the Essiac formula to the nurse and said it had cured her disease. The patient said the formula came from an Ontario Ojibwa Native American medicine man.
   
   
   
   • In 1934, the nurse opened a cancer clinic in Ontario and gave Essiac to patients free of charge. In 1938, the Royal Cancer Commission of Canada visited the clinic but found little evidence that Essiac was effective. The nurse closed the clinic in 1942 but continued to give Essiac to patients until the late 1970s.
   
   
   
   • Between 1959 and the late 1970s, the nurse worked with an American doctor to study Essiac in the laboratory and in people and to promote its use. They also created the formula now called Flor•Essence. The results of their studies were not reported in any peer-reviewed scientific journals. Most scientific journals have experts who review research reports before they are published, to make sure that the evidence and conclusions are sound. This is called peer review. Studies published in peer-reviewed scientific journals are considered to be better evidence.
   
   
   
   • In 1977, the nurse gave the formula for Essiac to a company in Canada. In 1978, the government of Canada allowed this company to do clinical studies (research studies with people) on the safety and effectiveness of Essiac. In 1982, it withdrew its permission (see Question 6 ¹). This company tried to have Essiac approved as a drug by the US Food and Drug Administration (FDA), but did not get approval.
   
   
   
   • In the 1980s, companies making Essiac-like products began to sell the mixtures as health tonics. Because these companies did not make claims that it would treat or cure certain diseases, Essiac did not come under laws that regulate it as a drug.
   
   
   
3. What is the theory behind the claim that Essiac and Flor•Essence are useful in treating cancer?

   Supporters of Essiac and Flor•Essence say that when the herbs they contain are mixed in exact amounts, the mixtures make the immune system stronger, have anti-inflammatory effects (decrease swelling, redness, and pain), and show anticancer activity. Individual herbs in the Essiac and Flor•Essence formulas have been shown to have these effects, but some of these herbs also have been shown to help cancer grow. No results from controlled trials have been published in peer-reviewed scientific journals on the effect of the exact formulas of Essiac and Flor•Essence in patients with cancer or other health conditions. See the PDQ health professional summary on Essiac/Flor•Essence ² for more information on theory.

4. How are Essiac and Flor•Essence administered?

   Essiac and Flor•Essence are taken orally (by mouth) as herbal teas. According to the companies that make the teas, the proper dose of Essiac depends on why a person is taking it. The maker recommends that Essiac be taken for 12 weeks in a row. The maker of Flor•Essence states that adults may take between 30 and 360 milliliters (1 to 12 fluid ounces) of Flor•Essence tea a day, depending on individual needs, and may take it on an ongoing basis.

   The makers of Essiac and Flor•Essence state that the products can be used with other therapies. Some supporters of Essiac, however, recommend that patients avoid any other anticancer therapy (such as chemotherapy or radiation therapy) when taking Essiac, because it may interfere with immune system function and prevent Essiac from working effectively.

5. Have any preclinical (laboratory or animal) studies been conducted using Essiac or Flor•Essence?

   Research in a laboratory or using animals is done to find out if a drug, procedure, or treatment is likely to be useful in humans. Animal tumor models are used to learn how a cancer may progress and to test new treatments. These preclinical studies are done before any testing in humans is begun. The following laboratory and animal studies of Essiac have been reported:

   • In the mid 1970s, the Memorial Sloan-Kettering Cancer Center (MSKCC) in New York City tested dried and liquid samples of Essiac in 8 experiments involving the S–180 mouse sarcoma tumor model (a type of animal model used to study treatment). Researchers found that Essiac did not make the immune system more active and did not act as an anticancer drug.
   
   
   
   • In the early 1980s, researchers at MSKCC tested Essiac again. They found no anticancer activity after doing 17 studies that used a variety of animal leukemia models and other tumor models.
   
   
   
   • In 1983, the National Cancer Institute (NCI) tested a liquid sample of Essiac in the mouse P388 lymphocytic leukemia tumor system but found no anticancer activity. Very high doses of Essiac killed the test animals. Scientists, however, do not know how this finding applies to people who take more than the maker's recommended doses of Essiac.
   
   
   
   • In 2004, a laboratory study at Indiana University-Purdue University reported that Essiac slowed the growth of prostate cancer cells.
   
   
   

   Studies of Flor•Essence have shown differing results:

   • Two laboratory studies reported that Flor•Essence made tumor cells grow.
   
   
   
   • Another laboratory study reported that high doses of both Flor•Essence and Essiac herbal teas reduced the growth of cancer cells.
   
   
   
   • A 2004 animal study of Flor•Essence found that it increased breast tumor growth in rats.
   
   
   

   Laboratory and animal studies have reported on the effects of some of the chemicals found in the different herbs used to make Essiac and Flor•Essence. These studies report that certain chemicals may:

   • Prevent cell damage that can lead to cancer.
   • Reduce swelling, redness, and pain.
   • Have an effect on the body similar to the hormone estrogen.
   • Kill cancer cells.

   It is not known if taking Essiac and Flor•Essence products can give humans enough of the chemicals that produce these effects.

6. Have any clinical trials (research studies with people) of Essiac or Flor•Essence been conducted?

   No results of clinical studies (research studies with people) of Flor•Essence have been reported. In addition, no reports of clinical trials of Essiac have been reported in peer-reviewed scientific journals. Brief descriptions of one incomplete clinical trial and one review of reports on cancer patients who took Essiac have been published, however.

   • In 1978, the Canadian government gave permission to a Canadian company to begin studying Essiac for safety and effectiveness. In 1982, the government withdrew its permission after it found that the company was not keeping all batches of Essiac exactly the same and was not following the proper rules for clinical trials. A review of data from this incomplete study showed no clear evidence of improved survival in cancer patients who took Essiac. Findings also showed that Essiac was not toxic (harmful).
   
   
   
   • In the early 1980s, the Canadian government reviewed information on 86 cancer patients who had taken Essiac. This was a review of case summaries written by the doctors; the original patient records were not reviewed. The researchers reported that it was not clear if changes in the patients’ conditions were caused by Essiac or something else.
   
   
   
7. Have any side effects or risks been reported from Essiac or Flor•Essence?

   The only reported side effects caused by Essiac are nausea and vomiting. According to the company making Flor•Essence, side effects may include increased bowel movements, frequent urination, swollen glands, skin blemishes, flu-like symptoms, and slight headaches.

8. Is Essiac or Flor•Essence approved by the FDA for use as a cancer treatment in the United States?

   The U.S. Food and Drug Administration (FDA) has not approved Essiac or Flor•Essence to treat cancer or any other medical condition.

   Companies sell Essiac and Flor•Essence as health tonics or herbal dietary supplements, which the FDA regulates as foods, not drugs. Essiac or Flor•Essence would have to be approved by the FDA as a drug for companies to claim that the products treat or prevent a disease.

Glossary Terms

A disease caused by the human immunodeficiency virus (HIV). People with AIDS are at an increased risk for developing certain cancers and for infections that usually occur only in individuals with a weak immune system. Also called acquired immunodeficiency syndrome.

An animal with a disease either the same as or like a disease in humans. Animal models are used to study the development and progression of diseases and to test new treatments before they are given to humans. Animals with transplanted human cancers or other tissues are called xenograft models.

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 plant whose leaves, stems, and flowers have been used in some cultures to treat certain medical problems. Blessed thistle may have anti-inflammatory and anticancer effects. The scientific name is Cnicus benedictus. Also called cardin, holy thistle, spotted thistle, and St. Benedict's thistle.

The long, tube-shaped organ in the abdomen that completes the process of digestion. The bowel has two parts, the small bowel and the large bowel. Also called intestine.

Glandular organ located on the chest. The breast is made up of connective tissue, fat, and breast tissue that contains the glands that can make milk. Also called mammary gland.

Cancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare.

A plant whose seeds and root have been used in some cultures to treat certain medical problems. It may have antioxidant effects. The scientific name is Arctium lappa. Also called happy major and lappa.

The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.

Treatment with drugs that kill cancer cells.

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 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 study.

A clinical study that includes a comparison (control) group. The comparison group receives a placebo, another treatment, or no treatment at all.

To heal or restore health; a treatment to restore health.

Any of several diseases in which the kidneys make a large amount of urine. Diabetes usually refers to diabetes mellitus in which there is also a high level of glucose (a type of sugar) in the blood because the body does not make enough insulin or use it the way it should.

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.

The amount of medicine taken, or radiation given, at one time.

Any substance, other than food, that is used to prevent, diagnose, treat or relieve symptoms of a disease or abnormal condition. Also refers to a substance that alters mood or body function, or that can be habit-forming or addictive, especially a narcotic.

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.

A type of hormone made by the body that helps develop and maintain female sex characteristics and the growth of long bones. Estrogens can also be made in the laboratory. They may be used as a type of birth control and to treat symptoms of menopause, menstrual disorders, osteoporosis, and other conditions.

Liquid.

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.

Refers to the stomach and intestines. Also called GI.

An organ that makes one or more substances, such as hormones, digestive juices, sweat, tears, saliva, or milk. Endocrine glands release the substances directly into the bloodstream. Exocrine glands release the substances into a duct or opening to the inside or outside of the body.

Having to do with plants.

One of many chemicals made by glands in the body. Hormones circulate in the bloodstream and control the actions of certain cells or organs. Some hormones can also be made in the laboratory.

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

The root of this plant has been used in some cultures to treat certain medical problems. It may have anti-inflammatory and anticancer effects. The scientific name is Rheum palmatum or Rheum officinale. Also called Chinese rhubarb, da-huang, rhubarb, and Turkish rhubarb.

A type of seaweed. The stem-like parts of this plant have been used in some cultures to treat certain medical problems. It may have immunostimulatory and anticancer effects. The scientific name is Laminaria digitata.

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.

Cancer that starts in blood-forming tissue such as the bone marrow and causes large numbers of blood cells to be produced and enter the bloodstream.

A type of cancer in which the bone marrow makes too many lymphocytes (white blood cells).

A measure of volume for a liquid. A milliliter is approximately 950 times smaller than a quart and 30 times smaller than a fluid ounce. A milliliter of liquid and a cubic centimeter (cc) of liquid are the same.

The National Cancer Institute, part of the National Institutes of Health of the United States Department of Health and Human Services, is the Federal Government's principal agency for cancer research. The National Cancer Institute conducts, coordinates, and funds cancer research, training, health information dissemination, and other programs with respect to the cause, diagnosis, prevention, and treatment of cancer. Access the National Cancer Institute Web site at http://www.cancer.gov. Also called NCI.

A feeling of sickness or discomfort in the stomach that may come with an urge to vomit. Nausea is a side effect of some types of cancer therapy.

By or having to do with the mouth.

A measure of weight (one-sixteenth pound) and volume (one-eighth cup).

PDQ is an online database developed and maintained by the National Cancer Institute. Designed to make the most current, credible, and accurate cancer information available to health professionals and the public, PDQ contains peer-reviewed summaries on cancer treatment, screening, prevention, genetics, complementary and alternative medicine, and supportive care; a registry of cancer clinical trials from around the world; and directories of physicians, professionals who provide genetics services, and organizations that provide cancer care. Most of this information, and more specific information about PDQ, can be found on the NCI's Web site at http://www.cancer.gov/cancertopics/pdq. Also called Physician Data Query.

A publication that contains original articles that have been written by scientists and evaluated for technical and scientific quality and correctness by other experts in the same field.

Research using animals to find out if a drug, procedure, or treatment is likely to be useful. Preclinical studies take place before any testing in humans is done.

In medicine, the course of a disease, such as cancer, as it becomes worse or spreads in the body.

Cancer that forms in tissues of the prostate (a gland in the male reproductive system found below the bladder and in front of the rectum). Prostate cancer usually occurs in older men.

The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that travels in the blood to tissues throughout the body. Also called irradiation and radiotherapy.

Trifolium pratense. A plant with flowers that has been used in some cultures to treat certain medical problems. It is being studied in the relief of menopausal symptoms and may have anticancer effects. Also called purple clover, Trifolium pratense, and wild clover.

A cancer of the bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue.

A person who has studied science, especially one who is active in a particular field of investigation.

A plant that has been used in some cultures to treat certain medical problems. It may have anticancer effects. The scientific name is Rumex acetosella. Also called dock and sorrel.

A problem that occurs when treatment affects healthy tissues or organs. Some common side effects of cancer treatment are fatigue, pain, nausea, vomiting, decreased blood cell counts, hair loss, and mouth sores.

The inner bark of this plant has been used in some cultures to treat certain medical problems. It may have antioxidant effects. Also called gray elm, Indian elm, red elm, sweet elm, Ulmus fulva, and Ulmus rubra.

The percentage of people in a study or treatment group who are alive for a certain period of time after they were diagnosed with or treated for a disease, such as cancer. The survival rate is often stated as a five-year survival rate, which is the percentage of people in a study or treatment group who are alive five years after diagnosis or treatment. Also called overall survival rate.

An indication that a person has a condition or disease. Some examples of symptoms are headache, fever, fatigue, nausea, vomiting, and pain.

Treatment.

Having to do with poison or something harmful to the body. Toxic substances usually cause unwanted side effects.

An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumors may be benign (not cancerous), or malignant (cancerous). Also called neoplasm.

Cells, tissues, or animals used to study the development and progression of cancer, and to test new treatments before they are given to humans. Animals with transplanted human tumors or other tissues are called xenograft models.

Fluid containing water and waste products. Urine is made by the kidneys, stored in the bladder, and leaves the body through the urethra.

To eject some or all of the contents of the stomach through the mouth.

Parts of the flowering plant have been used in some cultures to treat certain medical problems. It may have anticancer effects. The scientific name is Nasturtium officinale. Also called Indian cress.