Essiac

Common Names

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 have shown that Essiac has antioxidant and cytotoxic properties. But results of 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 showed 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.
Brand Name

Essiac, Vitaltea®, Flor-Essence®
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 root, 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 treatment
- Health maintenance
- HIV and AIDS
- Immunostimulation
Mechanism of Action

Rhubarb and sheep sorrel contain anthraquinones that stimulate both secretion of mucosa and water, as well as peristalsis. Additional activities of anthraquinones isolated from rhubarb include stimulation of interleukins (IL-1, IL-6) and tumor necrosis factor (TNF) in vitro, and tumor necrosis against sarcoma 37, breast cancer, and Ehrlich cell lines in murine models. Burdock root was shown to induce hypoglycemia in animal models. The tannin extract may induce macrophage response and the lignan and sesquiterpene extracts were shown to inhibit platelet activating factor (PAF) in vitro ⁽¹⁾ ⁽²⁾. Essiac was also shown to inhibit cytochrome P450 (CYP450) enzymes in vitro ⁽⁶⁾.
Adverse Reactions
- Case Report: Anorexia, nausea, myalgia, fatigue, and generalized abdominal pain in a 59-year old following consumption of Essiac tea for six months. Her 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

Cytochrome P450: 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
1. 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.
2. Locock RA. Essiac. Can Pharm J 1997;130:18-19,51.
3. 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.
4. 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.
5. 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.
6. Seely D, Kenney DA, Myers SP, et al. In vitro analysis of the herbal compound Essiac. Anticancer Res 2007;27(6B):3875-82.
7. 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.
8. 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.
9. Al-Sukhni W, Grunbaum A, Fleshner N. Remission of hormone-refractory prostate cancer attributed to Essiac. Can J Urol 2005;12(5):2841-2.
10. 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.
11. 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.
12. 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.
13. Kessenich CR, Higgs D. Herbal tea components and liver function. Nurse Pract. 2010 Aug;35(8):10-1.
14. Flora Flor*Essence®. Burnaby, Canada: Flora Manufacturing & Distributing Ltd. http://www.florahealth.com/product_categories.cfm. Accessed August 7, 2019.