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Chaparral is a herb that comes from the creosote bush in the western deserts of the USA.

Native Americans have used chaparral for many years to relieve pain and inflammation. They also use it to treat illnesses including colds, digestive problems and cancer.

Many internet sites advertise and promote it as a way to treat or prevent cancer. But there is no research to prove that it works or if it is safe to use. There is no scientific evidence to support its use for the treatment of cancer.

Chaparral can cause serious side effects such as damage to your liver and kidneys. We don’t recommend it to treat or prevent any type of cancer.

In 1992, the Food and Drug Administration (FDA) in the USA sent out a warning to encourage the removal of all chaparral products from the market. In 2005, Health Canada also issued a warning not to take products containing chaparral. Despite this, chaparral is still easy to buy in shops and over the internet.

How you have chaparral

You can buy chaparral from health food shops, pharmacies and over the internet as:

  • a tablet or capsule
  • dried leaves for making tea
  • a liquid (tincture) made from chaparral leaves dissolved in alcohol
  • capsules with added antioxidants such as vitamin C

The cost varies depending on where you buy it. For example, over the internet you can buy 100 capsules for between £4.50 and £10.

Possible side effects

The US Food and Drug Administration (FDA) say that chaparral shouldn’t be swallowed or injected. It is toxic and can cause serious and permanent kidney and liver damage, possibly even death.

It can also cause:

  • diarrhoea
  • weight loss
  • fever
  • skin rashes and itching
  • tiredness
  • acute inflammation of the liver (hepatitis)
  • kidney cysts
  • kidney cancer

Research into chaparral for people with cancer

An American study in 1970 tested chaparral tea and tablets made of its main ingredient (called nordihydroguaiaretic acid or NDGA). The study looked at 45 people with advanced cancer. The US National Cancer Institute published the results.

Of the 45 people who took part, 4 found that their cancer got smaller. The effect lasted between 10 days and 20 months. But in the other 41 people, the tumours got bigger. Overall, the researchers found that chaparral wasn’t safe and did not work well for treating cancer.

A review of 18 case reports of people who took chaparral showed that it can cause severe, irreversible liver damage and failure. It can also cause kidney damage in some people.

Some laboratory studies seem to show that the main ingredient, NDGA, might have anti cancer properties. But there have been no clinical trials in humans to prove this.

In some lab studies it seemed that NDGA might help other cancer drugs to work. Researchers are looking into whether a pure form of NDGA might be useful as a cancer treatment.

But this is very early research. Positive results in a laboratory or on animals does not mean it will be a successful treatment for people with cancer.

There is an extract from the chaparral shrub called M4N. An American study in 2004 showed that it might be safe to use.

Researchers injected M4N into the tumours of 8 people with advanced head and neck cancer. These cancers had not responded to other types of treatment. The M4N appeared to shrink some tumours, and nobody on the trial had the serious liver damage that has been shown in other studies with chaparral.

A 2006 study showed that M4N might help to stop cancers from becoming resistant to certain types of chemotherapy. But we need more research.

It is important to test each active ingredient in the plant. When you take a complete plant as a medicine, you take hundreds of different chemicals together. Any of these could affect you, the cancer, or other medicines you are taking.

Manufactured drugs are checked to make sure they only contain pure ingredients. We don’t recommend that you take chaparral to treat or prevent any type of cancer.

Before you have chaparral

We don’t recommend that you replace your conventional cancer treatment with any type of alternative cancer therapy, including chaparal. Doing so could seriously harm you.

It is completely up to you to decide whether to use any alternative or complementary therapy. We recommend that you always check with your doctor before you start. That way, your doctor can have a full picture of your care and treatment.

A qualified herbal medicine practitioner can monitor your progress regularly and do some tests to make sure there are no harmful side effects. They also know when not to prescribe you a herb.

Relying on advice from staff in health food shops or information from the internet is very risky. The people involved in giving this advice often have little or no training.

Our advice is:

  • Be careful.
  • Check prices and the amounts each preparation contains.
  • Make sure you look at all the information available.
  • Talk to your cancer doctor before you buy or use any alternative or complementary therapy.
  • Only use herbal medicine from a trained practitioner who is registered with a professional organisation.
  • Only buy products that are registered under the Traditional Herbal Remedies (THR) scheme - these have been tested for quality and safety.

Who shouldn’t use chaparral

You shouldn’t use chaparral if you:

  • are pregnant or breastfeeding
  • have kidney or liver problems
  • are taking certain medicines
  • are diabetic – in animal studies chaparral has lowered blood sugar levels
  • are trying to become pregnant – chaparral may prevent ovulation which will lower your chance of getting pregnant

Chaparral can interfere with how some drugs work, especially those that can also affect your liver and kidneys. These include:

  • some antibiotics
  • non steroidal anti inflammatory drugs such as ibuprofen
  • a type of anti depressant called a monoamine oxidase inhibitor (MAOI)

Children shouldn’t have chaparral because of the possible side effects and the lack of scientific data to prove that it is safe.

Last reviewed: 
09 Jan 2015
  • Complete guide to complementary and alternative medicine (2nd edition)
    American Cancer Society, 2009

  • Chaparral-associated hepatotoxicity
    NM Sheikh and others
    Archives of Internal Medicine, 1997. Volume 157, Issue 6

  • Chaparral ingestion. The broadening spectrum of liver injury caused by herbal medications
    DW Gordon and others
    JAMA, 1995. Volume 273, Issue 6

  • Toxic acute hepatitis and hepatic fibrosis after consumption of chaparral tablets
    H. Kauma and others
    Scandinavian Journal of Gastroenterology, 2004. Volume 39, Issue 11

  • Cystic renal cell carcinoma and acquired renal cystic disease associated with consumption of chaparral tea: a case report
    AY smith and others
    Journal of Urology, 1994. Volume 152, Issue 6

  • Reversal of multidrug resistance by two nordihydroguaiaretic acid derivatives, M4N and maltose-M3N, and their use in combination with doxorubicin or paclitaxel
    CC Chang and others
    Cancer Chemotherapy and Pharmacology, 2006. Volume 58, Issue 5

  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. If you need additional references for this information please contact with details of the particular issue you are interested in.

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