Essiac and Flor Essence are herbal tea mixtures sold worldwide as herbal dietary supplements or health tonics, and which are often used as complementary treatments for AIDS, Cancer, Diabetes, and Gastrointestinal Diseases.

Essiac is comprised of 4 herbs: Burdock Root; Indian Rhubarb Root; Sheep Sorrel; and Slippery Elm (the inner bark).

Flor Essence reportedly contains the same 4 herbs found in Essiac plus 4 additional herbs: Watercress; Blessed thistle; Red clover; Kelp.

As with most natural remedies, batches of these mixtures may differ and contain the above herbs in different quantities or may contain additional ingredients, so the effect may not always be the exact same in different batches.

A History of the Medical Use of Essiac and Flor Essence

In 1922, the head nurse at a local hospital in the small town of Haileybury in northern Ontario, Rene Caisse, was given the Essiac formula by a breast cancer patient who swore that it had cured her cancer and told the nurse that the formula had come from an Ontario Ojibwa Native American Medicine Man.

Rene placed the piece of paper on which she had written the formula, the names of 8 different herbs, in her pocket and forgot about it for two years until her aunt had been diagnosed with a major stomach growth. Her liver was involved too, and the specialists had given up hope. Rene and her aunt’s physician, Dr. Arnold Fisher, decided to try the tea.


Rene gathered the herbs from the wild, or bought them from a supply house, brewed the tea, and gave it to her aunt while the doctor monitored.

Her aunt’s health turned around in two months and she was declared free of the health challenge in every area of her body a year later. She lived for another 20 years.

Caisse and Dr. Fisher studied the Essiac in both a laboratory setting as well as in humans, between 1959 and the late 1970s.

They started experimenting with the recipe to make it the best it could be, as they wanted to find out which herb was the most effective.

During this process they also discovered that certain of the herbs needed to be taken orally to assist the cleansing activity. This led to the development of a four-herb formula, now known as Flor Essence, which always was administered as one herb by injection and three by mouth.

Over the next few decades, more and more people found out about the tea and more and more seriously challenged patients were being sent to Rene’s clinic for help. Some of them did not survive, but many others did, living another 15 to 20 years after the doctors had declared them terminal.

During these early years, the remedy, came to the attention of the medical authorities. Twice Rene was almost arrested for practicing medicine without a license. However, when the authorities with the arrest warrants understood what she was doing, and that she was not charging for her services, they went away without serving the warrants.

Rene also went to the Passavant hospital in Chicago where she treated and helped 30 terminal people. The doctors who monitored her work there concluded that Rene’s solution prolonged life, relieved pain, and broke down abnormal masses of tissue. Many petitions were signed, one of them even garnering 55,000 names. She had support from people in all walks of life.

Nevertheless, in the end Rene’s work was officially stopped by the Canadian government in 1942. The Commission which looked at Rene’s product refused to approve her remedy without full disclosure of the ingredients, and Rene was fearful of her remedy either disappearing or being changed if she disclosed it. She had kept the formula secret, and therefore was no longer permitted to help people. In 1958, she formed a partnership with Dr. Charles Brusch of Cambridge, MA. He had been the personal physician to President John F. Kennedy.

Dr. Brusch was a well-known and much respected physician, with degrees in surgery, internal medicine, obstetrics, and psychiatry. He was known for his open mindedness about other treatment modalities, and for his use of them in his clinic. When Rene and Dr. Brusch began their partnership, he knew she had begun with eight herbs, and he also knew that the Indians did not know about injections, so they perfected the formula by bringing it as close as they could to the original 8 herbs with which she had started in 1922. The partners worked on the blend to make it as synergistically active as possible, so it could all be taken orally just as the Indians had originally used it.

In 1978 Rene Caisse passed away at the age of 91, leaving the full eight-herb formula they had developed, worked on, and perfected, to her partner Dr. Charles Brusch. In 1984, Dr. Brusch was interviewed by a long-time radio producer and broadcaster, Elaine Alexander, who broadcast out of Vancouver, Canada. Elaine aired programs on many controversial alternative methods, including a couple on this herbal tea.


The listener response to the programs on the tea, from people suffering with some major health challenges, was massive. Over the next 2 years, seven 2-hour programs were produced covering every aspect of this incredible tea. Elaine and Dr. Brusch became friends. He was impressed by her long research of the subject, and her genuine interest. In 1988, they legally became partners, deciding to try to get this herbal formulation out to the public as a tea rather than as a medicine.

The great demand created for this tea persuaded Elaine to look for an herbal company with integrity to manufacture and distribute it for her. In 1992 she was introduced to Flora Manufacturing & Distributing Ltd., and signed a contract with them. Flora was well recognised and respected for their stringent quality standards and state-of-the-art technology. The manufacturing facility is certified by Quality Assurance International, a third party organic certification agency. Flora also has contracts with organic growers who supply the highest quality herbs, which are guaranteed for purity and potency.

At this time many varieties of the four herbs formula were emerging on the market, so to avoid confusion, the final formula, as developed and expanded by Rene and Dr. Brusch was named Flor Essence Tea.

Essiac/Flor Essence as a Complementary Therapy


Champions of Essiac and Flor Essence say that when the herbs are mixed in precise amounts, the mixtures have anti-inflammatory effects (decrease swelling, redness, and pain), strengthen the immune system, and evidence anticancer activity.

Essiac tea is one of the most common herbal treatments that patients employ in their self-treatment of cancer.

In 2004, the Mayo clinic estimated that about 10% of cancer patients enrolled in phase I drug trials were using Essiac.

Ingredients in Essiac Tea Recipe

  • 1 ½ pounds cut burdock root (Arctium lappa is a natural blood detoxifier)
  • 1 pound powdered sheep sorrel (Rumex acetosella is a powerful antioxidant)
  • ¼ pound powdered slippery elm (Ulmus fulva is a powerful antioxidant)
  • 1 ounce powdered Turkish (Indian) rhubarb root (Rheum pamatum is a phytochemical that is naturally astringent, anti-microbial, antifungal, and anti-inflammatory)

Directions to Make Essiac Tea

  • Mix all four herbs thoroughly, store in a tightly sealed glass container away from light
  • For a quart of tea, you need 1 ounce of herbal blend
  • For a gallon of tea, you need 4 ounces of herbal blend
  • Bring desired amount of water to a rolling boil in a steel or cast iron pot for 15 minutes
  • Cover with a lid, steep at least 12 hours
  • The following day, reheat the water but do not boil
  • Allow to settle, then strain out herbs (there will be sediment in the bottom)
  • Pour into tightly sealed glass or ceramic containers and cool
  • Refrigerate and use as recommended (sweetened with honey or natural sugar to taste)


Laboratory, animal, and clinical (human) studies with Essiac and Flor Essence have not reported clear evidence of an anticancer effect.

  • In the mid-1970s, the Memorial Sloan-Kettering Cancer Center (MSKCC) in New York City tested dried and liquid samples of Essiac in 8 experiments. Researchers found that Essiac did not make the immune system more active and did not act as an anticancer drug.
  • In the early 1980s, the Canadian government reviewed information on 86 cancer patients who had taken Essiac. This was a review of case summaries written by the doctors; the original patient records were not reviewed. The researchers reported that it was not clear if changes in the patients’ conditions were caused by Essiac or something else.
  • In 2004, a laboratory study at Indiana University-Purdue University reported that Essiac slowed the growth of prostate cancer cells.
  • Two laboratory studies reported that Flor Essence made tumour cells grow while another laboratory study reported that high doses of both Flor Essence and Essiac herbal teas reduced the growth of cancer cells.
  • A literature review conducted by the University of Texas Center for Alternative Medicine Research (UT-CAM) identified 107 references on the principal herbs used in Flor Essence. Participants in the University of Texas survey reported feeling and coping better, with increased energy.
  • Recent clinical research conducted with the Russian Ministry of Health revealed that Flor Essence Tea helps support the immune system. A study conducted by the University of British Columbia in Canada found Flor Essence Tea to possess powerful antioxidant properties.

Laboratory and animal studies have reported on the effects of some of the chemicals found in the different herbs used to make Essiac and Flor Essence. These studies report that certain chemicals may:

  • Prevent cell damage that can lead to cancer.
  • Reduce swelling, redness, and pain.
  • Have an effect on the body similar to the hormone oestrogen.
  • Kill cancer cells.

Whether taking Essiac and Flor Essence products can supply humans with sufficient of the chemicals that produce these effects is unclear.

How is Essiac/Flor Essence Administered?


Essiac and Flor Essence are usually taken by mouth as herbal teas.One can buy the mixtures of herbs with which to make the tea or one could also just get hold of the herbs yourself and make the tea from scratch like the original ojibwa native americans used to do.

According the tea manufacturers, the correct dose of Essiac depends on the reason for which it is being taken, and they recommend that Essiac be taken for 12 weeks in a row.

Essiac also comes as an organic, non-toxic, drug free herbal remedy which contains no additives or preservatives in the form of a Herbal Supplement Powder or a Herbal Extract Formula, both of which are  taken to help support the Immune System.

Side Effects or Risks

Some individuals have reported nausea and vomiting caused from taking Essiac. According to the manufacturers of Flor Essence, side effects may include increased bowel movements, frequent urination, swollen glands, skin blemishes, flu-like symptoms, and slight headaches.


Please note that the Little Fighters Cancer Trust shares information regarding various types of cancer treatments on this blog merely for informational use.

LFCT does not endorse or promote any specific cancer treatments – we believe that the public should be informed but that the option is theirs to take as to what treatments are to be used.

Always consult your medical practitioner prior to taking any other medication, natural or otherwise.