Essiac tea is an herbal tea that has gained widespread popularity among natural health enthusiasts in recent years.

Proponents, or those in favor of the herbal tea, claim that it can kill cancer cells, stimulate immunity, and aid detoxification.

However, others consider it a questionable cancer therapy, noting that evidence to support its use is insufficient.

This article looks at the ingredients, benefits, and potential side effects of Essiac tea.

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Essiac tea is a popular herbal tea touted for its purported anticancer properties.

In the 1920s, Canadian nurse Rene Caisse promoted Essiac tea as a natural cancer treatment, claiming that it was given to her by a patient who originally received it from an Ontario Ojibwa medicine man.

Though the tea is still said to be a Native American natural remedy, evidence to back up this claim is limited.

Essiac tea is a blend of different herbs, including:

  • burdock root
  • slippery elm
  • sheep sorrel
  • Indian rhubarb

In addition to its purported anticancer properties, Essiac tea is also believed to enhance detoxification, boost immune function, and reduce inflammation (1).

The tea is usually sold in powder form, but capsule and tea bag varieties are also available.

Traditionally, it’s made by combining 2 ounces (57 mL) of concentrated tea with the same amount of heated spring water.

Manufacturers of the product recommend drinking 1 to 12 ounces (30 to 360 mL) daily for best results (1).


Essiac tea is made from a blend of herbs claimed to fight cancer, improve immunity, increase detoxification, and decrease inflammation.

Test-tube and animal studies show that Essiac tea is rich in antioxidants and may offer anti-inflammatory properties (2, 3).

Its four main ingredients have all been associated with various health-promoting properties.

These primary ingredients are:

  • Burdock root. This root contains compounds shown to promote blood circulation, improve skin texture, and stabilize blood sugar (4).
  • Slippery elm. Revered for its medicinal properties, slippery elm is rich in disease-fighting antioxidants and may aid in treating inflammatory bowel disease (5).
  • Sheep sorrel. Also known by its scientific name, Rumex acetosella, sheep sorrel has been shown to have potent antiviral properties in test-tube studies (6, 7).
  • Indian rhubarb. One recent animal study found that Indian rhubarb is high in antioxidants and may inhibit the growth of liver cancer cells in rats (8).

Essiac tea is high in antioxidants and made from a blend of herbs with potential health-promoting properties.

Research on the anticancer effects of Essiac tea has had conflicting results.

For example, one test-tube study showed that the tea had antioxidant properties and prevented damage to cells and DNA, which could potentially help protect against cancer (2).

An older test-tube study noted that Essiac tea blocked the growth of breast and leukemia cancer cells when administered in high concentrations (9). A more recent animal study found the same growth-blocking effects, though research on human subjects is still needed (10).

There is also some anecdotal evidence that certain types of cancer have responded well to Essiac tea — including one case report of a man who went into remission from prostate cancer and attributed it to the tea (11).

However, plenty of studies have found little to no effect of Essiac tea on cancer development, including one review of 17 animal studies that detected no anticancer properties (1).

Multiple other animal and test-tube studies have also shown that Essiac tea has no effect on cancer cells, and in some cases, it may even stimulate the growth of breast cancer cells (1, 12, 13, 14).

Additionally, because human studies are currently unavailable, more high-quality studies are needed to understand how Essiac tea may impact cancer development in the general population.


Animal and test-tube studies have had conflicting findings on the effects of Essiac tea on cancer cell growth and development. Human studies on its proposed effects are needed.

Drinking Essiac tea has been associated with many side effects.

These include nausea, vomiting, frequent urination, increased bowel movements, skin issues, flu-like symptoms, headaches, and swollen glands (1).

In addition, the tea’s manufacturers also note that women who are pregnant or breastfeeding should avoid this product (1).

Some also recommend avoiding Essiac tea if you have breast cancer, as animal and test-tube studies have found that it may stimulate the growth of breast cancer cells (13, 14).


Essiac tea may cause side effects and is not recommended for women who are pregnant or breastfeeding. Animal and test-tube studies note that it may increase the growth of breast cancer cells.

Most of the studies available on Essiac tea, including the ones referred to in this article, are older, and current research is needed. In addition, most available studies are in animals and individual cells in a lab rather than in humans.

Additionally, though its effects on cancer have been studied, research on other health claims of Essiac tea — such as its detoxifying and immune-boosting properties — is lacking.

In fact, many of the purported health benefits of Essiac tea stem solely from anecdotal reports.

Furthermore, the product has not been approved for the treatment of cancer or other medical conditions by the Food and Drug Administration (FDA) (1).

It may also be associated with many side effects, including nausea, vomiting, frequent urination, and increased bowel movements (1).

Therefore, more research on Essiac tea’s potential effects on health is needed before it can be recommended.


Current research on the effects of Essiac tea is limited to animal and test-tube studies, as well as anecdotal reports.

Essiac tea is made from a blend of herbs with potential health benefits, though only its purported anticancer effects have been studied — with conflicting results.

In fact, the tea has been shown to stimulate breast cancer growth in test-tube and animal studies. Additionally, it may cause unpleasant side effects.

Therefore, it’s best to consult with your doctor before consuming Essiac tea, especially if you:

  • are taking any medications
  • are pregnant or breastfeeding
  • have underlying health conditions

Additionally, if you notice any side effects or symptoms, talk with your doctor about whether decreasing your dosage or stopping use altogether may be right for you.