Essiac
Purported Benefits, Side Effects, and More
For Patients & Caregivers
Tell your healthcare providers about any dietary supplements you’re taking, such as herbs, vitamins, minerals, and natural or home remedies. This will help them manage your care and keep you safe.
What is it?
Essiac has not been shown to treat or prevent cancer.
Essiac was developed in the 1920s by Rene Caisse, a Canadian nurse, and promoted as an alternative cancer treatment. It contains four botanicals: burdock root, sheep sorrel, slippery elm, and rhubarb. Laboratory studies suggest Essiac has antioxidant and cytotoxic properties. However, studies on its antiproliferative effects are conflicting: Essiac prevented growth of prostate cancer cells, but stimulated growth of breast cancer cells. In a study of breast cancer patients, Essiac did not improve quality of life or mood. Despite unsubstantiated claims, Essiac remains a popular anticancer therapy.
What are the potential uses and benefits?
- To treat cancer
Laboratory studies show conflicting results. An observational study of breast cancer patients did not find any improvement in quality of life with Essiac. - To treat HIV and AIDS
Evidence is lacking to support this claim. - To stimulate the immune system
In laboratory studies, rhubarb, an ingredient of Essiac, suppressed activity of part of the immune system. Human studies are lacking. - As a tonic
Evidence is lacking to support this claim.
What are the side effects?
Case Report
A 59-year-old woman reported symptoms of anorexia, nausea, myalgia, fatigue, and generalized abdominal pain following consumption of Essiac tea for six months. Her symptoms resolved after discontinuing the tea.
The manufacturer of Flor Essence states that users may experience increased bowel movements, frequent urination, swollen glands, skin blemishes, flu-like symptoms, or slight headaches.
What else do I need to know?
Do Not Take if:
- You are undergoing chemotherapy: In a case report, levels of a chemotherapy drug were increased in the blood of a patient also taking Essiac, with the potential for increased toxicity.
For Healthcare Professionals
Brand Name
Clinical Summary
Essiac was developed in the 1920s by Rene Caisse, a Canadian nurse, and promoted as an alternative cancer treatment. It is a formulation of four botanicals: burdock root, sheep sorrel, slippery elm bark, and rhubarb root (1) (2).
Essiac demonstrated antioxidant (12) and cytotoxic properties in vitro (6) (11), but stimulated growth of human breast cancer cells both via estrogen receptor (ER)-dependent and ER-independent pathways (3). Studies of its antiproliferative effects on prostate cancer cells also yielded conflicting data (7) (8). Remission of hormone-refractory prostate cancer was reported in a patient (9), but a retrospective study of breast cancer patients found that Essiac did not improve quality of life or mood (10).
Despite unsubstantiated claims (5), Essiac remains a popular anticancer therapy.
Purported Uses and Benefits
- Cancer
- Maintain health
- HIV, AIDS
- Immunostimulation
Mechanism of Action
Rhubarb and sheep sorrel contain anthraquinones that stimulate secretion of mucosa and water, as well as peristalsis. In vitro and animal models suggest anthraquinones isolated from rhubarb may stimulate IL-1, IL-6, and tumor necrosis factor. Burdock root induced hypoglycemia in animal models. The tannin extract may induce macrophage response and lignan and sesquiterpene extracts inhibited platelet activating factor in vitro (1) (2). Other in vitro studies show that Essiac can inhibit CYP450 enzymes (6).
Adverse Reactions
Case Report
Anorexia, nausea, myalgia, fatigue, and generalized abdominal pain in a 59-year old woman following consumption of Essiac tea for six months. Symptoms resolved after discontinuing the tea (13).
The manufacturer of Flor Essence states that users may experience increased bowel movements, frequent urination, swollen glands, skin blemishes, flu-like symptoms, or slight headaches (14).
Herb-Drug Interactions
CYP450: Decreased clearance of an experimental chemotherapy drug was reported in a patient taking Essiac (4). This may be due to inhibition of cytochrome P450 enzymes by Essiac (6).
References
- Tamayo C, et al. The chemistry and biological activity of herbs used in Flor-essence herbal tonic and Essiac. Phytotherapy Res 2000;14:1-14.
- Locock RA. Essiac. Can Pharm J 1997;130:18-19,51.
- Kulp KS, Montgomery JL, Nelson DO, et al. Essiac and Flor-Essence herbal tonics stimulate the in vitro growth of human breast cancer cells. Breast Cancer Research and Treatment 2006; 98:249-259.
- Geyer C, et al. Dose-schedule optimization the hexacyclic camptothecin (CPT) analog dx-8951f: a phase I and pharmacokinetic study with escalation of both treatment duration and dose (meeting abstract). Proc Annu Meet Am Soc Clin Oncol. 1999;18.
- Kaegi E. Unconventional therapies for cancer: 1. Essiac. The Task Force on Alternative Therapies of the Canadian Breast Cancer Research Initiative. CMAJ 1998;158:897-902.
- Seely D, Kenney DA, Myers SP, et al. In vitro analysis of the herbal compound Essiac. Anticancer Res 2007;27(6B):3875-82.
- Ottenweller J, Putt K, Blumenthal EJ, et al. Inhibition of prostate cancer-cell proliferation by Essiac. J Altern Complement Med 2004 Aug;10(4):687-91.
- Eberding A, Madera C, Xie S, et al. Evaluation of the antiproliferative effects of Essiac on in vitro and in vivo models of prostate cancer compared to paclitaxel. Nutr Cancer 2007;58(2):188-96.
- Al-Sukhni W, Grunbaum A, Fleshner N. Remission of hormone-refractory prostate cancer attributed to Essiac. Can J Urol 2005;12(5):2841-2.
- 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.
- Taj J, Cheung S, Wong S, Lowe C. In vitro comparison of Essiac and Flor-Essence on human tumor cell lines. Oncol Rep 2004 Feb;11(2):471-6.
- Leonard SS, Keil D, Mehlman T, et al. Essiac tea: Scavenging of reactive oxygen species and effects on DNA damage. J Ethnopharmacol 2006 ;103(2):288-96.
- Kessenich CR, Higgs D. Herbal tea components and liver function. Nurse Pract. 2010 Aug;35(8):10-1.
- Flora Flor*Essence®. Burnaby, Canada: Flora Manufacturing & Distributing Ltd. https://www.florahealth.com/. Accessed February 25, 2021.