Other common name(s): greasewood, creosote bush, jarilla, hediondilla, gobernadora
Scientific/medical name(s): Larrea divaricata coville, Larrea tridentata (DC) coville
Chaparral is an herb that comes from the leaves of the creosote bush, an evergreen desert shrub. The term "chaparral" refers to a group of plants dominated by evergreen shrubs that have small, stiff leaves. They grow in dense clusters to heights of 4 to 8 feet in the American West and Southwest, as well as in parts of Mexico and South America.
Chaparral is considered a dangerous herb that can cause irreversible, life-threatening liver damage and kidney damage. The U.S. Food and Drug Administration (FDA) has cautioned against the internal use of chaparral. Research has not found it to be an effective treatment for cancer or any other disease.
A clinical study of nordihydroguaiaretic acid (NDGA), one of the chemicals in chaparral, concluded that it was not useful in treating people with cancer, although research continues.
How is it promoted for use?
Proponents claim that chaparral can help relieve pain, reduce inflammation, aid congestion, increase urine elimination, and slow the aging process. It is also promoted as an anti-cancer agent and an antioxidant (a compound that blocks the action of free radicals, activated oxygen molecules that can damage cells). Some promoters call it a “cleanser” or detox herb.
Some researchers think NDGA might make other anti-cancer drugs more effective, but this theory still needs to be tested with clinical trials in people who are getting cancer treatment.
What does it involve?
Chaparral is sold in capsule, liquid, powder, or tablet form. Chaparral also can be made into a bitter and unpleasant-tasting tea or a tincture, a solution of chemicals from chaparral leaves dissolved in alcohol. Chaparral is also sometimes found with other herbs in “anti-cancer tea”.
What is the history behind it?
Native Americans used chaparral as an herbal remedy. They heated the leaves and applied them to the skin to treat wounds, bronchitis, coughs skin disorders, venereal sores, warts, blemishes, and ringworm. Heated stems were inserted into tooth cavities to relieve pain, and the leaves and stems were boiled to make tea to relieve rheumatism and other conditions, including colds, bronchitis, digestive problems, and cancer.
According to individual reports, chaparral tea was used widely in the United States from the late 1950s to the 1970s as an alternative anti-cancer agent. Experimental studies in the 1960s showed that chaparral could cause problems with kidney and liver function. Because of this, the FDA removed nordihydroguaiaretic acid (NDGA) from its “Generally recognized as sate” list.
The growth of interest in alternative medicine led to increased use of chaparral in the 1980s. By the early 1990s, there had been many reports of chaparral-linked illnesses, and the FDA issued a warning. This resulted in sellers voluntarily removing many chaparral products from stores. Despite many concerns and warnings, chaparral has become available again, and is advertised and sold from Internet sites.
What is the evidence?
Available scientific evidence does not support the idea that chaparral can prevent or slow the growth of cancer in humans, nor does it support chaparral as effective in treating other medical conditions.
In 1970, researchers from the University of Utah published results of a clinical study sponsored by the National Cancer Institute on chaparral tea and NDGA. People with advanced, incurable cancer drank chaparral tea or took doses of pure NDGA by mouth. Of the 45 people who were evaluated, only 4 had a small decrease in the size of their tumors. These regressions lasted between 10 days and 20 months. But in others treated with chaparral, the tumors grew larger. The authors concluded that chaparral tea was not an effective anti-cancer agent.
Some studies in the lab have suggested NDGA may possess anti-cancer properties. But studies of NDGA have had conflicting results. According to a 1990 government report, some researchers reported that NDGA inhibited cancer growth in animals. Others found that low levels of NDGA actually stimulated the growth of some types of tumor cells, although higher concentrations had the opposite effect. More recent cell culture studies using cancer cells grown in the lab suggest NDGA may make other anti-cancer drugs work better, and researchers are still looking into the potential uses of purified NDGA. While these studies show some promise, clinical studies are needed to find out whether NDGA may help people with cancer.
More recently, a new chemical has been made from NDGA. It is called terameprocol (EM-1421), and is being studied as a cancer treatment, but is still in the early stages of laboratory testing.
Are there any possible problems or complications?
Although chaparral is still widely available, the FDA has recommended since 1968 that it not be swallowed or taken internally by any other route. Chaparral can be highly toxic and has been reported to cause severe and permanent liver disease that can be fatal. It has also been linked to kidney damage, including cysts in the kidney and kidney failure.
One case study reported that severe hepatitis developed in a 60-year-old woman who had taken chaparral for 10 months. She eventually required a liver transplant. In a later review of 18 case reports of adverse reactions associated with taking chaparral, researchers concluded that the herb is linked with irreversible liver damage and liver failure. Since these warnings were published, there have been fewer cases of liver damage reported.
Chaparral may cause dangerous interactions with a number of other medicines and herbs. Blood-thinning medications (anticoagulants); non-steroidal anti-inflammatory medicines (pain medicines such as aspirin, ibuprofen, naproxen, and others); diabetic drugs; and certain antidepressants (MAO inhibitors) are thought to be likely to cause problems while taking chaparral. Always tell your doctor and pharmacist about any herbs you are taking.
Other side effects of chaparral can include fatigue, stomach pain, diarrhea, weight loss, fever, itching, rash, and allergic reactions. This herb should be avoided, especially by women who are pregnant or breast-feeding.
Relying on this type of treatment alone and avoiding or delaying conventional medical care for cancer may have serious health consequences.
To learn more
More information from your American Cancer Society
The following information on complementary and alternative therapies may also be helpful to you. These materials may be found on our Web site (www.cancer.org) or ordered from our toll-free number (1-800-227-2345).
The ACS Operational Statement on Complementary and Alternative Methods of Cancer Management
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Sun Y, Giacalone NJ, Lu B. Terameprocol (tetra-O-methyl nordihydroguaiaretic acid), an inhibitor of Sp1-mediated survivin transcription, induces radiosensitization in non-small cell lung carcinoma. J Thorac Oncol. 2011 Jan;6(1):8-14.
US Congress, Office of Technology Assessment. Unconventional Cancer Treatments: OTA-H-405. Washington, DC: US Government Printing Office; 1990.
Vickers A. Alternative Cancer Cures: “Unproven” or “Disproven”? CA: A Cancer Journal for Clinicians Volume 54, Issue 2, pages 110–118, March/April 2004
Note: This information may not cover all possible claims, uses, actions, precautions, side effects or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for consultation with your doctor, who is familiar with your medical situation.
Last Revised: 08/16/2011