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Essiac is a mixture of roots, bark and leaves that you boil to make a drinkable liquid.

Essiac is a herbal remedy originally from Canada. There is no scientific evidence to show that Essiac can treat, prevent or cure cancer in humans.

Its 4 main ingredients are:

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

A modified Essiac product called Flor Essence also includes the additional herbs:

  • watercress
  • blessed thistle
  • red clover
  • kelp

Some people call Essiac 'the tea of life' and claim it is a miracle cure for cancer. There have been reports of cancers completely disappearing after taking Essiac. But, it often turns out that the diagnosis was wrong in the first place, or that conventional cancer treatment, such as cancer drugs or radiotherapy, was more likely to have been the reason for the cancer disappearing.

Essiac was created by a Canadian nurse called Renee Caisse who named the remedy after herself. Essiac is her surname spelled backwards.

Essiac is now owned by a commercial company. Essiac is the registered trademark of Essiac Products Inc.

Why people with cancer use Essiac

Some people with cancer choose to have Essiac. These are some possible reasons.

Some people promote alternative therapies such as Essiac to cure or treat cancer. But there is no scientific evidence to prove that Essiac can do this. 

Some people believe that certain alternative or complementary therapies help boost the immune system which helps to fight their cancer.

There is no scientific evidence to prove this, partly because of lack of research. Until we have more evidence from research, we can't be sure exactly how complementary or alternative therapies might affect the immune system. 

Some people take Essiac because they feel it helps to:

  • relieve pain
  • shrink tumours
  • reduce weight loss (cachexia) in advanced cancer
  • improve health, energy levels and wellbeing
  • detoxify and cleanse the body

There is currently no scientific evidence to prove that Essiac can do this.

Your doctor might tell you that there are no further conventional cancer treatments that can cure your cancer. But, that there are treatments to control your symptoms.

The news that your cancer can’t be cured is difficult to accept. So it isn’t surprising that some people consider using alternative therapies.

They hope that it will help them to live longer even when there is no evidence that it can do this.

How you have Essiac

You can buy Essiac as a powder which you make into a tea. You drink it on an empty stomach, 2 hours before meals. The manufacturers recommend that you take 1 to 12 ounces (30 to 350mg) of this drink every day.

You can also buy it as a liquid and mix it with spring or distilled water and keep it in the fridge. The recommended dose in this form is usually about 1 ounce, taken up to 3 times a day.

Essiac manufacturers say you can take it for a period of 1 to 2 years.

Possible side effects

There are a few reports of side effects from taking Essiac

The makers say that it might cause:

  • swollen glands
  • flu like symptoms
  • headaches
  • skin redness and inflammation
  • passing urine or opening your bowels more often than usual

Essiac is not recommended for people with kidney or liver problems. This is because the plants in Essiac contain chemicals called oxalates which can damage the liver and kidneys.

In 1 case report a woman had lack of appetite, feeling sick, tiredness, and abdominal pain after taking Essiac tea for 6 months. Her symptoms got better when she stopped taking the tea.

Another case report suggests that Essiac may slow down the rate at which your body breaks drugs down. This can mean that some drugs will be more potent or that their effects last longer in your body. The case report suggests that Essiac may block liver enzymes called cytochrome p450. These enzymes are important in getting some cancer drugs out of your system.

Talk to your cancer specialist about this if you are thinking of taking Essiac.

Using Essiac safely

The makers of Essiac and Flor essence say that Essiac can be used alongside cancer treatment. But some websites advise that you stop your cancer treatments while you have it.

Stopping cancer treatment such as cancer drugs, chemotherapy radiotherapy could be very harmful to your health. We do not recommend that you replace your conventional cancer treatment with any type of alternative cancer therapy.

It is understandable that you and the people who care about you might want to try something if you think it might help. Only you can decide whether or not to use an alternative cancer therapy such as Essiac.

But, remember that Essiac is not accepted or licensed as a drug. It is usually sold as a nutritional supplement. And, there is no scientific evidence to support the claims made by its promoters.

Research into Essiac in cancer treatment

Most of the websites that promote Essiac use unsupported opinions and anecdotal evidence.

The Memorial Sloan Kettering Cancer Centre tested Essiac in the laboratory. They found it had no anti cancer properties.

The National Cancer Institute (NCI) in the U.S tested Essiac several times. Their testing found that Essiac had no anti cancer effects. One study in 2006 found that when Essiac was added to breast cancer cells in test tubes, it stimulated the cancer cells to grow. 

The CAM-Cancer organisation reviews scientific research evidence. In 2011, they looked at all the reviews about Essiac and Flor Essence. They couldn’t find any well carried out clinical studies and said that some of its ingredients could cause harm.

Researchers in the USA in 2009 also reviewed all studies into Essiac and Essiac preparations. They found there were no well carried out clinical trials to show that Essiac can help with cancer. 

We need to run well designed clinical trials to test Essiac and its individual herbs to test if Essiac works or is safe for people with cancer.

The cost of Essiac

Compared to some other alternative remedies Essiac isn’t expensive. A 1 month supply of Essiac tea costs around £6.00. The suppliers also recommend that you buy special bottles and an infuser as a starter kit to make the tea. This costs around £10.00.

A word of caution

Always ask your doctors and nurses about whether any complementary or alternative cancer therapy you are thinking of using might interact with your other treatments.

If your treatment team don’t have the information you need they can direct you to other people who can help.

​When it comes to any type of complementary or alternative therapy:

  • be careful
  • be wary of any websites or people who claim that it can treat or cure your cancer
  • make sure you look into all the information that is available first
  • be wary of buying products on websites, especially if they are asking for a lot of money

We are concerned that alternative therapies, like this one, lack scientific evidence to prove they help. It is understandable that you and the people who care about you may want to try anything if you think it might help treat or cure your cancer.

Useful organisations

We don’t know of any specific Essiac organisations or websites in the UK. But we have a list of international organisations and websites that you could use to look for more information.

Last reviewed: 
30 Jan 2015
  • Essiac and Flor-Essence herbal tonics stimulate the in vitro growth of human breast cancer cells. K.S Kulp and others. Breast cancer research and treatment, August 2006. Vol 98, (3): 249-59. 

  • The chemistry and biological activity of herbs used in Flor-Essence herbal tonic and Essiac. C.Tamayo and others. Phytotherapy Research, Feb 2000. Vol 14, (1):1-14. 

  • Essiac: systematic review by the natural standard research collaboration. C. Ulbricht and others. Journal of the Society for Integrative Oncology, Spring 2009, Vol 7 (2): 73-80.

  • CAM-CANCER - Complementary and Alternative Medicine for Cancer

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