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How It Works
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.
Purported Uses
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.
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.
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.
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
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).
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.
