Essiac Tea: Ingredients, Benefits, and Side Effects

Essiac tea is an herbal infusion that has drawn considerable attention among advocates of natural remedies in recent years.

Supporters claim the blend can destroy cancer cells, strengthen the immune system, and assist with detoxification.

Yet skeptics consider it a dubious cancer treatment, pointing out that evidence supporting these assertions is limited.

This article examines the components, suggested benefits, and possible adverse effects of Essiac tea.

What is Essiac tea?

Essiac tea is a well-known herbal mixture promoted for its alleged anticancer effects.

In the 1920s, Canadian nurse Rene Caisse popularized Essiac as a natural cancer remedy, claiming she received the recipe from a patient who had originally obtained it from an Ojibwa healer in Ontario.

Although the tea is often described as a Native American traditional remedy, proof for this origin story is limited.

Essiac is a combination of several herbs, typically including:

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

Beyond its supposed anticancer effects, Essiac is also claimed to support detoxification, enhance immune response, and reduce inflammation (1).

The product is commonly available as a powder, though capsule and tea-bag formats are offered as well.

Traditionally, preparation involves mixing about 2 ounces (57 mL) of concentrated tea with an equal volume of heated spring water.

Manufacturers often suggest consuming between 1 and 12 ounces (30 to 360 mL) each day for optimal effect (1).

Summary: Essiac tea consists of a mixture of herbs promoted to fight cancer, bolster immunity, enhance detoxification, and reduce inflammation.

Contains health-promoting compounds

Laboratory and animal research indicates Essiac tea is abundant in antioxidants and may exhibit anti-inflammatory activity (2, 3).

Each of its principal components has been linked to various potentially beneficial effects.

The main herbs include:

• Burdock root. This root contains chemicals that have been associated with improved blood flow, healthier skin, and blood sugar regulation (4).
• Slippery elm. Valued for therapeutic uses, slippery elm is packed with antioxidant compounds and may help in managing inflammatory bowel conditions (5).
• Sheep sorrel. Also called Rumex acetosella, sheep sorrel has shown strong antiviral activity in laboratory studies (6, 7).
• Indian rhubarb. One animal study reported that Indian rhubarb is rich in antioxidants and may suppress liver cancer cell growth in rats (8).

Summary: Essiac tea is antioxidant-rich and composed of herbs that show potential health advantages.

Mixed evidence on cancer-fighting properties

Studies examining Essiac tea’s anticancer effects have produced inconsistent outcomes.

For instance, a laboratory study demonstrated antioxidant activity and protection against cellular and DNA damage — findings that could theoretically lower cancer risk (2).

An earlier in vitro study reported that Essiac inhibited the growth of breast and leukemia cells at high concentrations (9). A more recent animal investigation observed similar growth-inhibiting effects, but human trials are lacking (10).

There are also anecdotal reports of cancers responding favorably to Essiac — including one case where a man reported remission of prostate cancer and attributed it to the tea (11).

However, numerous studies have found minimal or no anticancer effects of Essiac, including a review of 17 animal studies that detected no anticancer activity (1).

Several other animal and lab studies also indicated no impact on cancer cells, and in certain situations Essiac may promote growth of breast cancer cells (1, 12, 13, 14).

Because human clinical trials are currently absent, more rigorous research is necessary to determine how Essiac might affect cancer risk or progression in people.

Summary: Animal and laboratory findings on Essiac’s effect on cancer cells are contradictory. Well-designed human studies are required.

Potential side effects

Consumption of Essiac tea has been linked to a range of adverse effects.

Reported reactions include nausea, vomiting, increased urination, more frequent bowel movements, skin rashes, flu-like symptoms, headaches, and swollen lymph nodes (1).

Moreover, manufacturers advise that pregnant or breastfeeding women should avoid using Essiac (1); see also is tea safe during pregnancy for general guidance on tea use during pregnancy.

Some experts also caution against using Essiac if you have breast cancer, since laboratory and animal data suggest it could stimulate breast cancer cell proliferation (13, 14).

Summary: Essiac tea can cause adverse effects and is not advised for women who are pregnant or nursing. Animal and lab studies indicate it may encourage breast cancer cell growth.

Limited research on effectiveness

Many studies investigating Essiac are older, and contemporary research is lacking. Most evidence comes from animal experiments and cell-based studies rather than human trials.

Although its anticancer potential has received the most attention, examinations of other claimed benefits — such as detoxification and immune enhancement — are sparse.

Indeed, numerous supposed advantages of Essiac rely primarily on anecdotal evidence.

Additionally, Essiac is not approved by the U.S. Food and Drug Administration (FDA) for treating cancer or other medical conditions (1).

It may also produce side effects like nausea, vomiting, frequent urination, and increased bowel movements (1).

Consequently, more high-quality human research is needed before Essiac can be endorsed for health purposes.

Summary: Existing research on Essiac is limited to animal and laboratory studies and anecdotal accounts; more human research is necessary.

The bottom line

Essiac tea is an herbal blend composed of several plants that may offer health benefits, but evidence — especially regarding anticancer effects — is mixed.

Some studies have even shown it could promote breast cancer growth in laboratory and animal models. It can also lead to unpleasant side effects.

Therefore, consult your healthcare provider before using Essiac, particularly if you:

• are taking medications
• are pregnant or breastfeeding
• have existing medical conditions

If you experience any adverse reactions, discuss with your doctor whether reducing the dose or discontinuing use is advisable. For related herbal and digestive topics, you might also be interested in tea for constipation.