Natural Standard Monograph, Copyright © 2014 (www.naturalstandard.com). Commercial distribution prohibited. This monograph is intended for informational purposes only, and should not be interpreted as specific medical advice. You should consult with a qualified health care professional before making decisions about therapies and/or health conditions.
- Burdock root (Arctium lappa)synonyms/related terms: Akujitsu, anthraxivore, arctii, Arctium minus, Arctium tomentosa, bardana, Bardanae Radix, bardane, bardane grande (French), beggar’s buttons, burr, burr seed, chin, clot-burr, clotbur, cocklebur, cockle button, cocklebuttons, cuckold, daiki kishi, edible burdock, fox’s clote, grass burdock, great bur, great burdock, great burdocks, gobo (Japan), Grosse klette (German), happy major, hardock, hare burr, hurrburr, Kletterwurzel (German), lampazo (Spanish), lappola, love leaves, niu bang zi, oil of lappa, personata, Philanthropium, thorny burr, turkey burrseed, woo-bang-ja, wild gobo.
- Sheep sorrel (Rumex acetosella)synonyms/related terms: Acedera, acid sorrel, azeda-brava, buckler leaf, cigreto, common sorrel, cuckoo sorrow, cuckoo’s meate, dock, dog-eared sorrel, field sorrel, French sorrel, garden sorrel, gowke-meat, greensauce, green sorrel, herba acetosa, kemekulagi, Polygonaceae (family), red sorrel, red top sorrel, round leaf sorrel, Rumex scutatus, Rumex acetosa L., sheephead sorrel, sheep’s sorrel, sorrel, sorrel dock, sour dock, sour grass, sour sabs, sour suds, sour sauce, Wiesensauerampfer, wild sorrel.
- Slippery elm inner bark (Ulmus fulva)synonyms/related terms: Indian elm, moose elm, red elm, rock elm, slippery elm, sweet elm, Ulmaceae, Ulmi rubrae cortex, Ulmus fulva Michaux, Ulmus rubra, winged elm.
- Turkish rhubarb (Rheum palmatum)synonyms/related terms: Baoshen pill, Canton rhubarb, Chinesischer Rhabarber (German), Chinese rhubarb, chong-gi-huang, common rhubarb, da-huang, Da Huang, daio, Da huang Liujingao, English rhubarb, Extractum Rhei Liquidum, Himalayan Rhubarb, Indian rhubarb, Japanese rhubarb, Jiang- Zhi Jian-Fel Yao (JZJFY), Jinghuang tablet, medicinal rhubarb, pie rhubarb, Polygonaceae (family), Pyralvex, Pyralvex Berna, racine de rhubarbee (French), RET (Rhubarb extract tablet), rhabarber, rhei radix, rhei rhizoma, rheum, Rheum australe, Rheum emodi Wall, Rheum officinale Baill, Rheum rhabarbarum, Rheum rhaponticum L., Rheum tanguticum Maxim, Rheum tanguticum Maxim. ex. Balf., Rheum tanguticum Maxim L., Rheum undulatum, Rheum x cultorum, Rheum webbianum (Indian or Himalayan rhubarb), rhizoma, rheirhubarbe de chine (French), rhubarb, rubarbo, ruibarbo (Spanish), shenshi rhubarb, tai huang, Turkey rhubarb.
- Essiac® contains a combination of herbs, including burdock root (Arctium lappa), sheep sorrel (Rumex acetosella), slippery elm inner bark (Ulmus fulva), and Turkish rhubarb (Rheum palmatum). The original formula was developed by the Canadian nurse Rene Caisse (1888-1978) in the 1920s (“Essiac” is Caisse spelled backwards). The recipe is said to be based on a traditional Ojibwa (Native American) remedy, and Caisse administered the formula by mouth and injection to numerous cancer patients during the 1920s and 1930s. The exact ingredients and amounts in the original formulation remain a secret.
- During investigations by the Canadian government and public hearings in the late 1930s, it remained unclear if Essiac® was an effective cancer treatment. Amidst controversy, Caisse closed her clinic in 1942. In the 1950s, Caisse provided samples of Essiac® to Dr. Charles Brusch, founder of the Brusch Medical Center in Cambridge, Massachusetts, who administered Essiac® to patients (it is unclear if Brusch was given access to the secret formula). According to some accounts, additional herbs were added to these later formulations, including blessed thistle (Cnicus benedictus), red clover (Trifolium pratense), kelp (Laminaria digitata), and watercress (Nasturtium officinale).
- A laboratory at Memorial Sloan-Kettering Cancer Center tested Essiac® samples (provided by Caisse) on mice during the 1970s. This research was never formally published, and there is controversy regarding the results, with some accounts noting no benefits, and others reporting significant effects (including an account by Dr. Brusch). Questions were later raised of improper preparation of the formula. Caisse subsequently refused requests by researchers at Memorial Sloan-Kettering and the U.S. National Cancer Institute for access to the recipe.
- In the 1970s, Caisse provided the formula to Resperin Corporation Ltd., with the understanding that Resperin would coordinate a scientific trial in humans. Although a study was initiated, it was stopped early amidst questions of improper preparation of the formula and inadequate study design. This research was never completed. Resperin Corporation Ltd., which owned the Essiac® name, formally went out of business after transferring rights to the Essiac® name and selling the secret formula to Essiac Products Ltd., which currently distributes products through Essiac® International.
- Despite the lack of available scientific evidence, Essiac® and Essiac-like products (with similar ingredients) remain popular among patients, particularly in those with cancer. Essiac® is most commonly taken as a tea. A survey conducted in the year 2000 found almost 15% of Canadian women with breast cancer to be using Essiac®. It has also become popular in patients with HIV and diabetes, and in healthy individuals for its purported immune-enhancing properties, although there is a lack of reliable scientific research in these areas.
- There are more than 40 Essiac-like products available in North America, Europe, and Australia. Flor-Essence® includes the original four herbs (burdock root, sheep sorrel, slippery elm bark, Turkish rhubarb) as well as herbs that were later added as “potentiators” (blessed thistle, red clover, kelp, watercress). Virginias Herbal E-Tonic™ contains the four original herbs along with echinacea and black walnut. Other commercial formulations may include additional ingredients, such as cat’s claw (Uncaria tomentosa).
Uses based on scientific evidence
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare professional.
There is a lack of properly conducted published human studies using Essiac® for cancer. Currently, there is not enough evidence to recommend for or against the use of this herbal mixture as a therapy for any type of cancer.
*Key to grades:
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use (it may not work);
F: Strong scientific evidence against this use (it likely does not work).
For full grading rationale, click here.
Uses based on tradition or theory
The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified health care professional
AIDS/HIV, appetite stimulant, arthritis, asthma, blood cleanser, chelating agent (heavy metals), chronic fatigue syndrome, detoxification, diabetes, energy enhancement, Hodgkin’s disease, immune system enhancement, increasing lifespan (survival), kidney diseases, lupus, Lyme disease, nutritional supplement, paralysis, reduction of chemotherapy side effects, supportive care in advanced cancer patients, thyroid disorders, well-being.
The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare professional before starting a new therapy. Consult a healthcare professional immediately if you experience side effects.
- There are no reports of allergy to Essiac® in the published scientific literature, although reactions individuals with allergy to members of the Asteraceae/Compositae family, such as ragweed, potentially can occur due to any of the included herbs. Anaphylaxis has been reported after rhubarb leaf ingestion, and there are reports of allergic reactions to sorrel products taken by mouth. Contact dermatitis (skin rash after direct contact) has been reported with exposure to burdock, slippery elm bark, and rhubarb leaves. Cross-sensitivity to burdock may occur in chrysanthemums, marigolds, and daisies.
Side Effects and Warnings
- The safety of Essiac® is not well studied scientifically. Safety concerns are based on theoretical and known reactions associated with herbal components of Essiac®: burdock root (Arctium lappa), sheep sorrel (Rumex acetosella), slippery elm bark (Ulmus fulva), and Turkish rhubarb (Rheum palmatum). However, the safety and toxicities of these individual herbs are also not well studied. Various Essiac-like products may contain different or additional ingredients, and patients are advised to carefully review product labels.
- Potentially toxic compounds present in Essiac®include tannins, oxalic acid, and anthraquinones. Tannins, present in burdock, sorrel, rhubarb, and slippery elm, may cause stomach upset and in high concentrations may lead to kidney or liver damage. In theory, long-term use of tannins may increase the risk of head and neck cancers, although there are no documented human cases.
- Oxalic acid contained in rhubarb, slippery elm, and sorrel, can cause serious adverse effects when taken in high doses (particularly in children). Oxalic acid toxicity/poisoning may be associated with nausea, vomiting, mouth/throat burning, dangerously low blood pressure, blood electrolyte imbalances, seizure, throat swelling that interferes with breathing, and liver or kidney damage. Deaths from oxalic acid poisoning have been reported in an adult man eating soup containing sorrel and in a four year-old child eating rhubarb leaves. The amount of oxalic acid in Essiac® preparations is not known. In cases of suspected oxalic acid poisoning, medical attention should be sought immediately. Regular intake of oxalic acid may increase the risk of kidney stones.
- Anthraquinones in rhubarb root or sheep sorrel may lead to diarrhea, intestinal cramping, and loss of fluid and electrolytes (such as potassium). Use of rhubarb may lead to discoloration of the urine (bright yellow or red) or of the inner mucosal surface of the intestine (a condition called melanosis coli). Fluoride poisoning has been reported with the use of rhubarb fruit juice. Rhubarb products manufactured in China have been contaminated with heavy metals. Chronic use of rhubarb products may lead to dependence.
- Based on animal research and limited human study, burdock may cause either increases or reductions in blood sugar levels. Caution is advised in patients with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugar. Serum glucose levels may need to be monitored by a healthcare professional, and medication adjustments may be necessary. Diuretic effects (increasing urine flow) and estrogen-like effects have been reported with oral burdock use in patients with HIV.
- Reports of anticholinergic reactions (such as slow heart rate and dry mouth) with the use of burdock products in the 1970s are believed to be due to contamination with belladonna alkaloids, which resemble burdock and can be introduced during harvesting. Burdock itself has not been found to contain constituents that would be responsible for these reactions.
Pregnancy and Breastfeeding
- There is not enough scientific evidence to recommend the safe use of Essiac® or Essiac-like products during pregnancy and breastfeeding, and there are potential risks from the included herbs. Oxalic acid and anthraquinone glycosides in the included herbs may be unsafe during pregnancy. Rhubarb and burdock may lead to contraction of the uterus; some publications note that whole slippery elm bark can lead to abortion, although there is limited supporting scientific evidence.
Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare professional before starting a new therapy.
Interactions with Drugs
- Essiac® interactions are not well studied scientifically. Most potential interactions are based on theoretical and known reactions associated with herbal components of Essiac®: burdock root (Arctium lappa), sheep sorrel (Rumex acetosella), slippery elm bark (Ulmus fulva), and Turkish rhubarb (Rheum palmatum). However, the interactions of these individual herbs are also not well studied. Various Essiac-like products may contain different or additional ingredients, and patients are advised to carefully review product labels.
- Essiac® may interfere with the way the body processes certain drugs using the liver’s “cytochrome P450” enzyme system. As a result, the levels of these drugs may be increased in the blood, and may cause increased effects or potentially serious adverse reactions. Patients using any medications should check the package insert and speak with a healthcare professional or pharmacist about possible interactions. This is based on a report of one patient in a research study taking the experimental drug DX-8951f (metabolized by CYP3A4 and CYP1A2), who experienced toxic side effects and drug clearance that was 4 to 5 times slower than in other patients. This patient was also taking “Essiac tea,” although further details are not available and it is not clear if the patient was taking Essiac® or an Essiac-like product.
- Anthraquinones in rhubarb root or sheep sorrel may lead to diarrhea, dehydration, or loss of electrolytes (such as potassium), and may increase the effects of other laxative agents. Burdock has been associated with diuretic effects (increased urine flow) in one human report, and in theory may cause excess fluid loss (dehydration) or electrolyte imbalances (such as changes in blood potassium or sodium levels). These effects may be increased when burdock is taken at the same time as diuretic drugs such as chlorothiazide (Diuril®), furosemide (Lasix®), hydrochlorothiazide (HCTZ), or spironolactone (Aldactone®). The laxative and diuretic properties of herbs in Essiac® may lead to low potassium blood levels that are potentially dangerous in people taking digoxin or digitoxin.
- Based on animal research and limited human study, burdock may either lower or raise blood sugar levels. Caution is advised when using medications that may also affect blood sugar. Patients taking drugs for diabetes by mouth or insulin should be monitored closely by a qualified healthcare professional. Medication adjustments may be necessary.
- Based on limited human evidence that is not entirely clear, burdock may have estrogen-like properties, and may act to increase the effects of estrogenic agents including hormone replacement therapies such as Premarin® or birth control pills.
- Essiac® may also interact with antibiotics, angiotensin converting enzyme (ACE) inhibitors, antacids, corticosteroids, heart-regulating agents, or agents used for cancer including radiotherapy or chemotherapy. Essiac® may increase the risk of kidney or liver damage when taken with other agents that also affect the kidney or liver.
- There is early evidence suggesting that Essiac® may have a positive interaction when used with nifedipine, an agent used for high blood pressure during pregnancy, although more studies are needed to confirm this finding. Based on human evidence, the combination of rhubarb with anti-psychotic agents used in the management of schizophrenia may show promise.
Interactions with Herbs and Dietary Supplements
- Based on one human report, Essiac® may interfere with the way the body processes certain herbs or supplements using the liver’s “cytochrome P450” enzyme system. As a result, the levels of other herbs or supplements may become too high in the blood. It may also alter the effects that other herbs or supplements possibly have on the P450 system.
- Anthraquinones in rhubarb root or sheep sorrel may lead to diarrhea, dehydration, or loss of electrolytes (such as potassium), and may increase the effects of agents with possible laxative properties.
- Burdock has been associated with diuretic effects (increased urine flow) in one human report, and in theory, may cause excess fluid loss (dehydration) or electrolyte imbalances (such as changes in blood potassium or sodium levels) when used with other diuretic herbs or supplements.
- The laxative and diuretic properties of herbs in Essiac® may lead to low potassium blood levels that are potentially dangerous in people taking cardiac glycoside-containing herbs.
- Based on animal research and limited human study, burdock may either lower or raise blood sugar levels. Caution is advised when using herbs or supplements that can also alter blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment.
- Because burdock may contain estrogen-like chemicals, the effects of other agents believed to have estrogen-like properties may be altered.
- In theory, use of rhubarb and sheep sorrel may decrease the absorption of minerals such as calcium, iron, and zinc.
- Essiac® may also interact with herbs or supplements with certain effects, such as antibacterial, antacid, steroid, or heart-regulating effects. There is unclear evidence as to whether Essiac® interacts with agents used for cancer, and caution is advised when combining treatments. Essiac® may increase the risk of kidney or liver damage when taken with other agents that also affect the kidney or liver. Some preparations contain added ingredients, such as blessed thistle, red clover or cat’s claw, which are thought to increase the effectiveness of the original formula, but supportive evidence is lacking.
- This information is based on a professional level monograph edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).
Natural Standard developed the above evidence-based information based on a systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.
- Boon H, Stewart M, Kennard MA, et al. Use of complementary/alternative medicine by breast cancer survivors in Ontario: prevalence and perceptions. J Clin Oncol 2000;18(13):2515-2521.
- Bryson PD. Burdock root tea poisoning. JAMA 1978;240(15):1586.
- Bryson PD, Watanabe AS, Rumack BH, et al. Burdock root tea poisoning. Case report involving a commercial preparation. JAMA 5-19-1978;239(20):2157.
- De Jager R, Cheverton P, Tamanoi K, et al. DX-8951f: summary of phase I clinical trials. Ann N Y Acad Sci 2000;922:260-273.
- Kaegi E. Unconventional therapies for cancer: 1. Essiac. The Task Force on Alternative Therapies of the Canadian Breast Cancer Research Initiative. CMAJ 4-7-1998;158(7):897-902.
- Karn H, Moore MJ. The use of the herbal remedy ESSIAC in an outpatient cancer population (Meeting abstract). Proc Annu Meet Am Soc Clin Oncol 1997;16:A245.
- LeMoine L. Essiac: an historical perspective. Can Oncol Nurs J 1997;7(4):216-221.
- Ottenweller J, Putt K, Blumenthal EJ, et al. Inhibition of prostate cancer-cell proliferation by Essiac. J Altern Complement Med 2004;10(4):687-691.
- Rhoads PM, Tong TG, Banner W Jr, et al. Anticholinergic poisonings associated with commercial burdock root tea. J Toxicol Clin Toxicol 1984;22(6):581-584.
- Silver AA, Krantz JC. The effect of the ingestion of burdock root on normal and diabetic individuals: A preliminary report. Ann Int Med 1931;5:274-284.
- Tai J, Cheung S, Wong S, et al. In vitro comparison of Essiac and Flor-Essence on human tumor cell lines. Oncol Rep 2004;11(2):471-476.
- Tamayo C, Richardson MA, Diamond S, et al. The chemistry and biological activity of herbs used in Flor-Essence herbal tonic and Essiac. Phytother Res 2000;14(1):1-14.
- US Congressional Office of Technology Assessment. Essiac. US Government Printing Office 1990.
- Zarembski PM, Hodgkinson A. Plasma oxalic acid and calcium levels in oxalate poisoning. J Clin Pathol 1967;20(3):283-285.
- Zick SM, Sen A, Feng Y, et al. Trial of Essiac to ascertain its effect in women with breast cancer (TEA-BC). J Altern Complement Med 2006 Dec;12(10):971-80.