A genus of five evergreen shrubs, found in deserts of S America and southwestern N America. These highly adapted plants are difficult to cultivate outside their native habitats. Larrea tridentata (chaparral) is a suckering shrub that forms large stands. Individual plants in the Mohave Desert have been measured that have a 7.8m (26ft) radius and are estimated to be 11,700 years old. Plants are strongly aromatic, especially after rain, filling the air for many miles with creosote-like aroma. Substances that dissolve in the rain prevent the germination of the plant's own seeds, and the growth of other plants beneath its branches. The Mexican name gobernada, governess, refers to the plant's dominance over vast areas. Larrea species have a complex and unusual chemistry, containing nordihydroguaiaretic acid (NDGA), which ia a potent antioxidant and parasiticide. They are also rich in resins and other substances that make the plants unpalatable to herbivores. NDGA was the main antioxidant used in the food industry to prevent rancidity of fats and oils until the late 1960s. Desert tribes have long used these plants medicinally, notably in the form of "chaparral tea", which was regarded as a cure-all. Colonists found Larrea usefu for treating sexually transmitted diseases and malignant skin conditions. Eminent herbalists have described Larrea as "of low toxicity" (Thomas Bartram, Encyclopedia of Herbal Medicine, 1995), and having "a strong beneficial effect upon impaired liver metabolism" (Michael Moore, Medicinal Plants of the Desert and Canyon West, 1989). Nevertheless, a medicinal use of Larrea has been banned in a number of countries following five cases of hepatitis that were apparently due to taking chaparral.

A tea made from the leaves and twigs of the chaparral, and evergreen desert shrub, is an old Native American remedy for cancer that has also been used to treat arthritis, venereal disease, and colds. Chaparral may also contain substances that have anti-HIV and antitumor actions, and at least one study has shown that it can lower blood sugar. However, because chaparral tea can cause severe liver toxicity, its use is not recommended.

Thorny, open, spreading shrub with smooth bark, slender branches, and small, bifurcated, dark olive-green leaves, covered in strong-smelling, sticky, varnish-like resin. Yellow, 5-petaled flowers apear throughout the year after rain, but mainly from February to April, followed by fuzzy, pea-sized fruits.

Common Name:
Other Names:
Creosote bush, grease bush, greasewood, hediondilla
Botanical Name:
Larrea divaricata, Larrea tridentata
Native Location:
Desert areas of Mexico and USA (California, Utah, and Texas)
Larrea species do not appear to thrive outside their native habitat.
Larrea species do not appear to thrive outside their native habitat.
Young leafy twigs are cut and used fresh for teas and tinctures, or dried for tablets and ointment. The high resin content makes the twigs and foliage difficult to grind.
2-4m (6-12ft)
2-4m (6-12ft)
Parts Used:
Leafy twigs.
A strongly bitter, resinous, alterative herb that has potent antioxidant, antibiotic, antifungal, and anti-inflammatory, and anti-tumor effects; also antiseptic, especially on the respiratory and urinary systems.
Medicinal Uses:
Internally for kidney and gall stones, urinary tract infections, rheumatism and arthritis, diabetes, skin disorders, cancer (notably leukemia), liver ailments, and tetanus. Externally for wounds, dry skin, brittle hair and nails, arthritic pain, and foot odor.
To treat bronchitis, fever, diabetes, joint pain, and colds; as a "blood purifier" for infections of the genitourinary and respiratory tracts.
Typical Dose:
A typical dose of chaparral may range from 1 to 3 ml of a 1:5 dilution of tincture three times a day.
Possible Side Effects:
Chaparral's side effects include liver damage and, when used externally, contact dermatitis.
Drug Interaction:
Taking chaparral internally with these drugs may cause or increase liver damage:
Acarbose,(Prandase, Precose)
Acetaminophen,(Genepap, Tylenol)
Allopurinol,(Aloprim, Zyloprim)
Cyclosporine,(Neoral, Sandimmune)
Erythromycin,(Erythrocin, Staticin)
Etodolac,(Lodine, Utradol)
Fluconazole,(Apo-Fluconazole, Diflucan)
Fluphenazine,(Modecate, Prolixin)
Ganciclovir,(Cytovene, Vitrasert)
Gemfibrozil,(Apo-Gemfibrozil, Lopid)
Gentamicin,(Alcomicin, Gentacidin)
Ibuprofen,(Advil, Motrin)
Isoniazid,(Isoatamine, Nydrazid)
Ketoconazole,(Apo-Ketoconazole, Nizoral)
Ketoprofen,(Orudis, Rhodis)
Ketorolac,(Acular, Toradol)
Lamivudine,(Epivir, Heptovir)
Levodopa-Carbidopa,(Nu-Levocarb, Sinemet)
Lovastatin,(Altocor, Mevacor)
Meloxicam,(MOBIC, Mobicox)
Methotrexate,(Rheumatrex, Trexall)
Methyldopa,(Apo-Methyldopa, Nu-Medopa)
Morphine Hydrochloride,(Morphine Hydrochloride)
Morphine Sulfate,(Kadian, MS Contin)
Naproxen,(Aleve, Naprosyn)
Nitrofurantoin,(Furadantin, Macrobid)
Paclitaxel,(Onxol, Taxol)
Pantoprazole,(Pantoloc, Protonix)
Phenytoin,(Dilantin, Phenytek)
Piroxicam,(Feldene, Nu-Pirox)
Pravastatin,(Novo-Pravastatin, Pravachol)
Prochlorperazine,(Compazine, Compro)
Propoxyphene,(Darvon, Darvon-N)
Repaglinide,(GlucoNorm, Prandin)
Rifampin,(Rifadin, Rimactane)
Saquinavir,(Fortovase, Invirase)
Simvastatin,(Apo-Simvastatin, Zocor)
Tamoxifen,(Nolvadex, Tamofen)
Zidovudine,(Novo-AZT, Retrovir)
Lab Test Alterations:
May increase results of liver function tests including alkaline phosphatate, apartic acid transaminase (AST,SGOT), alanine amino-transferase (ALT,SGPT), total bilirubin, urine bilirubin, gamma-glutamyltransferase, and lactate dehydrogenase.
Disease Interactions:
May worsen liver disease.
Supplement Interactions:
May increase the risk of liver damage when combined with herbs and supplements that can cause hepatotoxicity (destructive effects on the liver), such as Bishop's Weed, Borage, Uva Ursi, and others.
Economic Uses:
Until synthetic antioxidants were developed, NDGA was important in the food industry for preventing rancidity in fats, oil, dairy products, frozen meats and fish, and in pharmaceutical preparations containing vitamin A and reserpine (from Rauvolfia serpentina, See, rauwolfia).
Encylopedia of Herbs by Deni Brown Copyright ©: 1995, 2001 Dorling Kindersley Limited pp 251-252
The Essential Herb-Drug-Vitamin Interaction Guide by Geo. T. Grosberg,MD and Barry Fox,PhD. Copyright ©2007 Barry Fox,PhD. Pp. 142-144