Expert Q&A

Essiac Tea: Helpful for Cancer Treatment?

What is Essiac tea? Can it help with cancer treatment?

-Sarah from California

Essiac Tea is one of the most popular alternative treatments for cancer. It has a strong word-of-mouth reputation with many testimonials claiming its ability to cure cancer. Essiac Tea was developed by a Canadian public health nurse named Rene Caisse (Essiac is Caisse spelled backwards). The original formula was based on an herbal tea developed by an Ojibwa Indian medicine man. Caisse reportedly treated her aunt's cancer with the tea. In 1924, she opened a clinic and began treating cancer patients with the herbal mixture.

There are many variations of this tea, but 4 herbs are common to all:

  • Burdock root
  • Sheep sorrel
  • Slippery elm inner bard
  • Turkish rhubarb root.

Other versions of the tea include Native Legend Tea, FlorEssence, Vitalitea, Tea of Life, and Herbal Essence, which contain additional herbs including watercress, blessed thistle, red clover, and kelp.

Alleged health benefits of essiac tea

Proponents of Essiac Tea claim that it can:

  • Strengthen immune function
  • Improve well-being
  • Relieve pain
  • Increase appetite
  • Reduce tumor size
  • Extend survival
  • Cleanse the blood
  • Promote cell repair
  • Restore energy levels
  • Detoxify the body.

Laboratory research results for essiac tea?

Currently, there is no scientific evidence to support these claims. Essiac Tea has been studied by the Memorial Sloan-Kettering Cancer Center, the National Cancer Institute, and Canadian health officials. All have failed to find any anti-tumor effects. According to the American Cancer Society's website, some of the individual ingredients in the tea have shown some anti-cancer effects in laboratory tests. However, there is no scientific evidence supporting its use as a cancer treatment in humans.

More recent research has shown that FlorEssence, a commonly used form of Essiac Tea did not stop the growth of breast cancer in mice. In fact, the study shows that drinking this product caused more and larger tumors to form in the mice that drank the tea before developing breast cancer.* (1, 2)

Potential side effects of essiac tea

Serious side effects of Essiac Tea are rare; however, some users have reported:

  • Headache
  • Nausea
  • Diarrhea
  • Constipation
  • Vomiting.

There are reports of more serious complications, including death from injecting the tea directly into the bloodstream.

Essiac tea: healthy but not a cancer therapy

Although Essiac Tea is not recommended as a treatment for cancer, Canadian health officials found that many people who drank it experienced an enhanced sense of well-being. Perhaps this effect is caused by the ritual of relaxing and sipping tea a few times a day, or by believing you are doing something beneficial for your health. In any case, there is probably little harm in using Essiac Tea in conjunction with conventional treatment. If you do choose to use it, be sure to tell your oncologist and never rely on this tea as a primary therapy for treating cancer.

*In light of the results of the recent breast cancer studies, it would be wise to avoid this tea after a breast cancer diagnosis.


(1) Flor-EssenceĀ® herbal tonic does not inhibit mammary tumor development, Breast Cancer Research and Treatment 88 (1):87-93, 2004, LM Bennett, JL Montgomery, SM, Steinberg , KS Kulp.

(2) EssiacĀ® and Flor-EssenceĀ® herbal tonics stimulate the in vitro growth of human breast cancer cells, Breast Cancer Research and Treatment, March 16, 2006, Kulp, KS, et al.

Erin Dummert RD, CD
Contributing Expert

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