Report on Chaparral Side Effects and Usage


Natural health supplements sometimes have unexpected side effects or interactions with medication that can lead to adverse reactions that are sometimes life threatening. The following is a list of cautions that you should be aware of before using chaparral (Larrea tridentata). These are referred to as drug/herb interactions.

Warning 1 – Counterindications: Pregnancy, breast-feeding, and the presence of liver or kidney problems.

Warning 2 – Hepatotoxic drugs: Using chaparral along with a medication that can harm the liver increases the risk of liver damage. Some medications that can harm the liver include:

  • acetaminophen (Tylenol and others)
  • amiodarone (Cordarone)
  • carbamazepine (Tegretol)
  • isoniazid (INH)
  • methotrexate (Rheumatrex)
  • methyldopa (Aldomet)
  • fluconazole (Diflucan)
  • itraconazole (Sporanox)
  • erythromycin (Erythrocin, Ilosone, others)
  • phenytoin (Dilantin)
  • lovastatin (Mevacor)
  • pravastatin (Pravachol)
  • simvastatin (Zocor)
  • And many others

Used as a natural health remedy: Chaparral has been used for the following benefits and conditions:

  • Anti-inflammatory agent (See other herbs for inflammation)
  • Antifungal agent
  • Arthritis
  • Chickenpox
  • Colds
  • Detoxification
  • Eliminating intestinal parasites
  • Fighting cancer
  • Preventing wound infections
  • Sexually transmitted diseases
  • Skin conditions
  • Stomach problems (cramps, gas)
  • Treating bacterial and viral illnesses
  • Tuberculosis
  • Urinary and respiratory infections
  • Weight loss

None of the above uses have been proven to be effective. Research has not found chaparral to be an effective treatment for any disease. However, Chaparral contains an ingredient called nor-dihihydroguairetic (NDGA), a potent anti-tumor agent. The Merck Manual lists this chemical as an anti-oxidant, and its therapeutic category is an anti-neoplastic. In general, an anti-neoplastic is defined as an agent that prevents the development, growth and proliferation of malignant cells.

Side Effects of Chaparral

Large amounts of chaparral have been reported to cause:

  1. diarrhea
  2. fever
  3. nausea
  4. stomach pain
  5. weight loss

The FDA has issued a warning against the use of chaparral, because this herb was linked to five cases of hepatitis. The FDA considers chaparral to be a dangerous herb that can cause irreversible, life-threatening liver damage and kidney damage.

Despite warnings, chaparral is still available in the U.S. Chaparral is sometimes an ingredient in homeopathic preparations. The safety concerns do not generally apply to homeopathic preparations containing chaparral due to the extreme dilutions.

Chaparral is also known as stinkweed.

As with any herb, a serious allergic reaction is possible. Seek immediate medical attention if you notice any symptoms of a serious allergic reaction. These may include a rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, or trouble breathing.

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For questions and answers about the side effects of herbs see the Herb Forum

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