Other common name(s): Essiac, Flor Essence, Tea of Life, Herbal Essence, Vitalitea
Scientific/medical name(s): none
Essiac is a mixture of herbs that are combined to make a tea. The original formula included burdock root (Arctium lappa L.), slippery elm inner bark (Ulmus fulva Michx.), sheep sorrel (Rumex acetosella L.), and Indian rhubarb root (Rheum palmatum L.). Watercress (Nasturtium officinale R.Br.), blessed thistle (Cnicus benedictus L.), red clover (Trifolium pratense L.), and kelp (Laminaria digitata [Hudson] Lamx.) were added to later recipes for a product sold as Flor Essence.
There have been no published clinical trials in conventional medical journals showing that either Essiac tea or Flor Essence helps in the treatment of cancer. Some of the specific herbs contained in the mixture have shown some anti-cancer effects in laboratory experiments. However, most laboratory studies of Essiac have found it didn’t work against cancer cells, and one reported that Flor Essence increased the growth of breast cancer cells. Available scientific evidence does not support its use for the treatment of cancer in humans.
How is it promoted for use?
Promoters claim Essiac strengthens the immune system, improves well-being, relieves pain, increases appetite, reduces tumor size, and extends survival. Some also claim that it cleanses the blood, promotes cell repair, restores energy levels, and detoxifies the body. The herbs contained in Essiac are supposed to relieve inflammation, lubricate bones and joints, stimulate the stomach, and eliminate excess mucous in organs, tissues, lymph glands, and nerve channels.
It was originally claimed Essiac worked by changing tumors into normal tissue. Proponents claimed a tumor would become larger and harder after a few doses of Essiac, then would soften, shrink, and be discharged by the body.
Essiac and Flor Essence are also promoted to treat AIDS and a variety of digestive system problems.
What does it involve?
Essiac is available in dry and liquid formulas, and methods of preparation and dosage vary by manufacturer. The dried herbs are brewed into tea. Some recommend using spring or non-fluoridated water, and most require refrigeration after brewing. A typical dose is 1 ounce taken 1 to 3 times per day. Practitioners advise that Essiac tea should be taken on an empty stomach, 2 hours before or after meals, for a period of at least 1 to 2 years. The manufacturer of Flor Essence recommends 1 to 12 ounces of tea daily.
You can buy Essiac and Flor Essence by mail order and in United States health food stores as a dietary supplement, and as a health tonic in Canada. There are also other herb mixtures with similar formulas that can be obtained from other sources.
What is the history behind it?
In 1922, a nurse named Rene Caisse from Ontario, Canada learned about an herbal formula from a patient. The patient claimed to have recovered from breast cancer by taking an Indian herbal tea from an Ojibwa medicine man. Caisse reportedly obtained the recipe and used it to treat her aunt's stomach cancer. In 1924, Caisse opened a clinic and began to offer cancer patients the herbal mixture, which she named Essiac (her last name spelled backward). She treated thousands of patients using her secret formula as a tea and as an injection. Canadian medical authorities investigated the clinic in 1938 and concluded that there was little evidence for the effectiveness of Essiac. Caisse gave her 4-herb formula to a manufacturer in Toronto in 1977, a year before her death.
Memorial Sloan-Kettering Cancer Center conducted animal testing of Essiac in 1959 and the mid-1970s but no anti-tumor effects were verified. In 1983, Canadian federal health officials requested that Essiac be tested by the U.S. National Cancer Institute (NCI), which found no evidence of anti-cancer activity in animal studies. Canadian health officials reviewed 86 case studies and concluded that there was no evidence that Essiac slowed the progression of cancer. They noted that there were few serious side effects, however, and that people may have benefited psychologically from the treatment.
What is the evidence?
Although there have been many testimonials, there have been no clinical trials testing the effectiveness of Essiac or Flor Essence. Reviews of medical records of people who have been treated with Essiac do not support claims that this product helps people with cancer live longer or that it relieves their symptoms.
Animal studies conducted at Memorial Sloan-Kettering Cancer Center and the NCI from the 1950s through the 1980s concluded that Essiac was not effective. The majority of subsequent studies have confirmed these findings. A recent laboratory study found that Essiac and Flor Essence actually increased growth of breast cancer cells. Flor Essence has not been tested as a cancer treatment in humans.
Some components of Essiac and Flor Essence have been tested individually in laboratory and animal studies. Some of these studies identified substances with anti-tumor or anti-inflammatory properties. However, these results do not mean that either of these formulas helps humans. To the contrary, the available scientific information indicates that these products are not helpful in treating people.
Are there any possible problems or complications?
Serious side effects are uncommon. Essiac may cause headache, nausea, diarrhea or constipation, vomiting, low blood sugar, liver damage, and kidney damage. Allergic rashes are possible. Rarely, serious allergic reactions have been reported.
In addition, the potential interactions between Essiac and other drugs and herbs should be considered. Some of these combinations may be dangerous. Always tell your doctor and pharmacist about any herbs you are taking.
Relying on this type of treatment alone and avoiding or delaying conventional medical care for cancer may have serious health consequences.
To learn more
More information from your American Cancer Society
The following information on complementary and alternative therapies may also be helpful to you. These materials may be found on our Web site (www.cancer.org) or ordered from our toll-free number (1-800-ACS-2345).
The ACS Operational Statement on Complementary and Alternative Methods of Cancer Management
Eberding A, Madera C, Xie S, Wood CA, Brown PN, Guns ES. Evaluation of the antiproliferative effects of Essiac on in vitro and in vivo models of prostate cancer compared to paclitaxel. Nutr Cancer. 2007;58:188-196.
Essiac. Memorial Sloan-Kettering Cancer Center Web site. Accessed at www.mskcc.org/mskcc/html/69215.cfm on July 15, 2011.
Essiac/flor-essence (PDQ®). National Cancer Institute Web site. Accessed at www.cancer.gov/cancertopics/pdq/cam/essiac/healthprofessional/allpages on July 15, 2011.
Herbal/plant therapies: essiac detailed scientific review. Complementary/Integrative Medicine Education Resources, The University of Texas M.D. Anderson Cancer Center Web site. Accessed at http://www.mdanderson.org/education-and-research/resources-for-professionals/clinical-tools-and-resources/cimer/therapies/herbal-plant-biologic-therapies/essiac-scientific.html on July 15, 2011..
Kaegi E on behalf of the Task Force on Alternative Therapies of the Canadian Breast Cancer Research Initiative. Unconventional therapies for cancer: 1. Essiac. CMAJ. 1998 Apr 7;158(7):897-902.
Kulp KS, Montgomery JL, Nelson DO, Cutter B, Latham ER, Shattuck DL, Klotz DM, Bennett LM. Essiac and Flor-Essence herbal tonics stimulate the in vitro growth of human breast cancer cells. Breast Cancer Res Treat. 2006;98:249-259. Epub 2006 Mar 16.
Seely D, Kennedy DA, Myers SP, Cheras PA, Lin D, Li R, Cattley T, Brent PA, Mills E, Leonard BJ. In vitro analysis of the herbal compound Essiac. Anticancer Res. 2007;27:3875-3882.
Ulbricht C, Weissner W, Hashmi S, Rae Abrams T, Dacey C, Giese N, Hammerness P, Hackman D, Kim J, Nealon A, Voloshin R. Essiac: systematic review by the natural standard research collaboration. J Soc Integr Oncol. 7(2):73-80, 2009.
Zick SM, Sen A, Feng Y, Green J, Olatunde S, Boon H. Trial of Essiac to ascertain its effect in women with breast cancer (TEA-BC). J Altern Complement Med. 2006;12:971-980.
Note: This information may not cover all possible claims, uses, actions, precautions, side effects or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for consultation with your doctor, who is familiar with your medical situation.
Last Revised: 10/14/2011