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


  • Chaparral is a herb
  • There is no scientific evidence to support its use as a treatment for cancer
  • Chaparral can have severe side effects

What is chaparral?

Chaparral is a herb that comes from the creosote bush. It grows 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 many illnesses. These include colds, diabetes, digestive problems and cancer.

In traditional medicine chaparral tea is used to treat gallbladder and kidney stones.

Why people with cancer use it

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 contains lignans. Lignans are chemicals found in plants. They have oestrogenic and anticancer effects.

The main lignan in chaparral is nordihydroguaiaretic acid (NDGA). It is a potent antioxidant. That means it protects cells from damage. Despite it being an antioxidant, it is toxic. In high doses NDGA causes liver damage.

M4N is a chemical made from NDGA. It is also called a derivative from NDGA. Researchers have tested M4N in laboratory studies on mouse and human cancer cells. They found that M4N can stop cancer cells from growing.

How you have it

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

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

Side effects

The US Food and Drug Administration (FDA) advises against swallowing or injecting chaparral. It is toxic and can cause severe and permanent kidney and liver damage, even death.

In 1992, the Food and Drug Administration (FDA) in the USA sent out a warning. They wanted 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.

Chaparral can also cause:

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

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. This is because of the possible side effects and the lack of scientific data to prove that it is safe.

Research into chaparral as a cancer treatment

An American study in 1970 tested chaparral tea and tablets. The researchers looked at 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. The researchers found that chaparral wasn’t safe and did not work well for treating cancer.

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

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

Researchers did a laboratory study in 2016. They found that NDGA stopped prostate cancer cells from spreading.

In another laboratory study in 2017 researchers developed a chemical from NDGA. It is called NDGA-P21. Researchers found that it stopped glioma cells from growing. Glioma is a type of brain cancer.

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.

M4N is a chemical made from NDGA. It is also called a derivative from NDGA. Early studies with M4N have shown that M4N stops the growth of several types of mouse and human cancer cells.

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. Nobody on the trial had the serious liver damage that has been shown in other studies with chaparral.

Researchers did another study in 2006. It showed that M4N might stop cancers from becoming resistant to certain types of chemotherapy. But we need more research.

Researchers think that the anti cancer effects of chaparral involve several cancer pathways. But we need more research before M4N can become a treatment for cancer.

How much it costs

Be cautious about believing information or paying for alternative cancer therapy on the internet.

Only buy products that are registered under the Traditional Herbal Remedies (THR) scheme - these have been tested for quality and safety.

A word of caution

It is understandable that you might want to try anything if you think it might help treat or cure your cancer. Only you can decide whether to use an alternative cancer therapy such as the chaparral.

You could harm your health if you stop your cancer treatment for an unproven treatment.

Many websites might promote chaparral as a cure for cancer. But no reputable scientific cancer organisations support any of these claims.

  • Complete guide to complementary and alternative medicine (2nd edition)
    American Cancer Society, 2009

  • Creosote bush lignans for human disease treatment and prevention: Perspectives on combination therapy

    J Gnabrea and others

    Journal of Traditional and Complementary Medicine Volume 5, Issue 3, July 2015, Pages 119-126

  • Nordihydroguaiaretic acid impairs prostate cancer cell migration and tumor metastasis by suppressing neuropilin 1

    L Xin and others

    Oncotarget. 2016 December 27; 7(52): 86225–86238.

  • NDGA-P21, a novel derivative of nordihydroguaiaretic acid, inhibits glioma cell proliferation and stemness

    Z Qi-Wen Zhao and others

    Laboratory Investigation volume 97, pages 1180–1187 (2017)

  • 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.

Last reviewed: 
16 Aug 2022
Next review due: 
16 Aug 2025

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