Chaparral (Larrea tridentata (DC) Coville, Larrea divaricata Cav)&Nordihydroguaiaretic acid (NDGA)
Natural Standard Bottom Line Monograph, Copyright © 2013 (www.naturalstandard.com). Commercial distribution prohibited. This monograph is intended for informational purposes only, and should not be interpreted as specific medical advice. You should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.
While some complementary and alternative techniques have been studied scientifically, high-quality data regarding safety, effectiveness, and mechanism of action are limited or controversial for most therapies. Whenever possible, it is recommended that practitioners be licensed by a recognized professional organization that adheres to clearly published standards. In addition, before starting a new technique or engaging a practitioner, it is recommended that patients speak with their primary healthcare provider(s). Potential benefits, risks (including financial costs), and alternatives should be carefully considered. The below monograph is designed to provide historical background and an overview of clinically-oriented research, and neither advocates for or against the use of a particular therapy.
1 aryl tetralin lignans, chaparral taxa, chaparral tea, chaparro, creosote, creosote bush, dwarf evergreen oak, el gobernadora (Spanish), falsa alcaparra (Spanish), flavonoids, furanoid lignans, geroop, gobernadora, greasewood, guaiaretic acid, guamis, gumis, hediondilla, hideonodo, hydrocarbons, jarillo, kovanau, kreosotstrauch, larrea, Larrea divaricata, Larrea glutiosa, Larrea mexicana, Larrea mexicana Moric, Larrea tridentate, Larrea tridentata (DC) Coville, lignans, maltose-M3N, M4N, NDGA, nordihydroguaiaretic acid, Nordy, palo ondo (Spanish), sapogenins, shoegoi, sonora covillea, sterols, tasago, triterpenes, volatile oils, wax esters, ya-tmep, yah-temp, Zygophyllaceae (family).
Chaparral is a shrub found in the desert regions of southwestern United States and Mexico. It was used by Native American populations for indications including chicken pox (varicella), colds, diarrhea, menstrual cramps, pain, rheumatic diseases, skin disorders, snake bites, and as an emetic. Chaparral tea was also used for purported effects of removing lysergic acid diethylamide (LSD) residue and thereby preventing recurrent hallucinations. Chaparral leaves have also been used externally for bruises, scratches, wounds, and hair growth.
The chaparral component nordihydroguaiaretic acid (NDGA) has been evaluated as a treatment for cancer but, due to risk of toxicity, it is considered unsafe and not recommended for use.
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Chaparral and one of its components called nordihydroguaiaretic acid (NDGA) have antioxidant ("free-radical scavenging") properties and have been proposed as cancer treatments. However, chaparral and NDGA have been linked with cases of kidney and liver failure, liver cirrhosis, kidney cysts, and kidney cancer in humans. In response to these reports, the U.S. Food and Drug Administration (FDA) removed chaparral from its "Generally Recognized as Safe" (GRAS) list in 1970. Chaparral and NDGA are generally considered unsafe and are not recommended for use.
*Key to grades:A: Strong scientific evidence for this use; B: Good scientific evidence for this use; C: Unclear scientific evidence for this use; D: Fair scientific evidence against this use (it may not work); F: Strong scientific evidence against this use (it likely does not work).
The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious and should be evaluated by a qualified health care professional.
Abdominal cramps, abortion inducing, abrasions, acne, actinic keratosis (a skin condition), alcohol withdrawal, allergies, antibacterial, anti-inflammatory, antioxidant, antiparasitic, antiseptic, antiviral, arthritis, autoimmune disorders, blood purifier, bowel cramps, breathing problems, bronchitis, bruises, burns, bursitis, cavities (preventive mouthwash), chicken pox, central nervous system disorders, cold sores, colds, coughs, cytomegalovirus, dandruff, decomposition, diabetes, diarrhea, diuretic (increasing urine flow), dysentery, enteritis, Epstein-Barr virus, fertility, flu, food additive, gas, gastrointestinal disorders, genitourinary infections, hair tonic, hallucinations (including due to LSD ingestion), heartburn, herpes simplex virus (cold sores), herpes zoster virus, immune function stimulation, immune system disorders, impetigo, indigestion, intestinal problems, Kaposi's sarcoma, kidney or bladder stones, leukemia, liver cleanser, liver metabolic function, melanoma, menstrual cramps, menstrual disorders, multidrug resistance (trastuzumab), neuritis, nutritional supplement, pain, painful joints, premenstrual syndrome (PMS), preservative, psoriasis, respiratory tract infections, rheumatic diseases, sciatica, skin disorders, skin infections, snakebite pain, stomach ulcer, tuberculosis, urinary tract infections, venereal disease, vomiting, wound healing (poultice).
The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.
Adults (18 years and older)
Safety has not been established for any dose. Small doses of tea have been used; for example, 1 teaspoon of chaparral leaves and flowers steeped in 1 pint of water for 15 minutes, consumed 1-3 cups daily for up to a maximum of several days. Chaparral tea has also been made by steeping 7-8 grams of crumbled dried leaves, stems, and twigs in one quart of hot water. As a water extract, chaparral might be consumed in the amount of one to three cups of chaparral tea per day for a period of two to three weeks, although this is not recommended.
A tincture has also been used; for example, 20 drops up to three times daily. These preparations may be associated with less toxicity, and possibly contain fewer allergenic compounds than capsules or tablets. Oil or powder forms of chaparral have also been used, applied to an affected area of skin several times daily.
Capsules or tablets may deliver large doses leading to toxicity, and are not recommended. Exposure to lignans, which may yield toxicity, appears to be greater from capsules or tablets than from chaparral tea.
Children (younger than 18 years)
Chaparral is not recommended for use in children, due to lack of scientific data and potential toxicity.
The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.
People with allergy/hypersensitivity to chaparral or any of its components including nordihydroguaiaretic acid (NDGA), nor-isoguaiasin, dihydroguaiaretic acid, partially demethylated dihydroguaiaretic acid, and demethoxyisoguaiasin may have allergic reactions to chaparral.
There are human case reports of allergic hypersensitivity (contact dermatitis) to chaparral and to its resin.
Side Effects and Warnings
Chaparral has been associated with multiple serious and potentially fatal adverse effects in animals and humans. Animals given the chaparral component nordihydroguaiaretic acid (NDGA) developed kidney or gastrointestinal cysts and liver cell death. In humans, chaparral has been associated with kidney and liver failure, liver cirrhosis, kidney cysts, and kidney cancer. Human case reports note rash and fever with use of chaparral. Nausea, vomiting, diarrhea, abdominal cramps, and mouth inflammation have also been reported in people consuming chaparral. Exposure to lignans, which may yield toxicity, appears to be greater from capsule or tablets than from decoctions of chaparral tea. The U.S. Food and Drug Administration (FDA) removed chaparral from the "Generally Recognized as Safe" (GRAS) list in 1970, and considers chaparral to be unsafe. Elevations of liver enzymes or altered kidney function tests (serum creatinine) may occur with chaparral.
Based on an animal study, chaparral may lower blood sugar levels. Caution is advised in patients with diabetes or hypoglycemia and in those taking drugs, herbs, or supplements that affect blood sugar. Serum glucose levels should be monitored closely and medication adjustments may be necessary. Aggravation of hypothyroidism may occur.
In theory, chaparral may also increase the risk of bleeding and may add to the effects of anticoagulants (blood thinners) or antiplatelet drugs. Use of chaparral with any of these drugs should be discussed with a healthcare professional.
Pregnancy and Breastfeeding
Chaparral cannot be recommended during pregnancy or breastfeeding because of the risk of birth defects or spontaneous abortion.
Chaparral may inhibit ovulation and decrease the chance that women will become pregnant.
Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.
Interactions with Drugs
Based on animal studies and human case reports, chaparral has been associated with kidney damage, cysts, cancer, and kidney failure. Theoretically, use of chaparral with other agents known to alter kidney function or induce toxicity should be avoided, including sulfa antibiotics, aminoglycoside antibiotics, COX-2 inhibitors, NSAIDs, and a number of other drugs. Patients who are using other medications and who are considering chaparral should consult with a qualified healthcare professional, including a pharmacist. Based on animal study and human case reports, chaparral has also been associated with liver damage. Theoretically, the use of chaparral with other agents known to induce liver toxicity should be avoided; these include amiodarone, carmustine, or danazol.
Based on animal study, chaparral may lower blood sugar levels. Caution is advised when using medications that may also lower blood sugar. Patients taking drugs for diabetes by mouth or injection should be monitored closely by a qualified healthcare professional. Medication adjustments may be necessary. Based on human research, chaparral may increase the risk of bleeding when taken with drugs that also increase the risk of bleeding. Some examples include aspirin, anticoagulants ("blood thinners") such as warfarin (Coumadin®) or heparin, anti-platelet drugs such as clopidogrel (Plavix®), and non-steroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®).
Based on animal research, chaparral may interfere with the way the body processes certain drugs using the liver's cytochrome P450 enzyme system. As a result, the levels of these drugs may be increased in the blood and may cause increased effects or potentially serious adverse reactions. Patients using any medications should check the package insert and speak with a qualified healthcare professional or pharmacist about possible interactions. Based on historical use, chaparral may interact with monoamine oxidase inhibitors (MAOIs), such as isocarboxazid (Marplan®), phenelzine (Nardil®), and tranylcypromine (Parnate®). There is also the possibility that blood pressure may become dangerously high if chaparral is taken with MAOIs, although there is limited research supporting this.
Chaparral may aggravate indomethacin-induced gastric ulcers and inhibit the metabolism of barbiturate drugs like phenobarbital. Effects of thyroid medications may be altered although this is unproven.
Chaparral may also interact with cancer, antiviral, gastrointestinal, immunosuppressant, thyroid, and abortion-inducing drugs.
Interactions with Herbs and Dietary Supplements
Based on animal studies and human case reports, chaparral has been associated with kidney damage, cysts, cancer, and kidney failure. Theoretically, the use of chaparral with other herbs or supplements known to alter kidney function or induce toxicity should be avoided; these include agents with high levels of tannins. Chaparral may increase the risk of high blood pressure if used with other herbs with this effect. Based on animal research and human case reports, chaparral has also been associated with liver damage. Theoretically, the use of chaparral with other herbs or supplements known to induce liver toxicity should be avoided.
Based on animal study, chaparral may lower blood sugar levels. Caution is advised when using herbs or supplements that may also lower blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment.
Based on human study, chaparral may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba, and fewer cases with garlic and saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases. Chaparral may also interact with vitamin K, which is necessary for blood clotting. By working against the action of vitamin K, chaparral may increase the risk of bleeding.
Based on animal research, chaparral may interfere with the way the body processes certain herbs or supplements using the liver's cytochrome P450 enzyme system. As a result, the levels of other herbs or supplements may become too high in the blood. It may also alter the effects that other herbs or supplements may have on the P450 system. Patients using any medications should check the package insert and speak with a healthcare professional or pharmacist about possible interactions.
Based on historical use, chaparral may interact with herbs or supplements with possible monoamine oxidase inhibitor (MAOI) effects, such as 5-HTP (5-Hydroxytryptophan) or DHEA (dehydroepiandrosterone). Chaparral may also interact with anti-cancer, antioxidant, antiviral, gastrointestinal, immunostimulant, immunosuppressant, and abortion-inducing herbs and supplements.
Effects of thyroid active agents may be altered although this is unproven.
This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).
Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.
Anonymous. From the Centers for Disease Control and Prevention. Chaparral-induced toxic hepatitis: California and Texas, 1992. JAMA 1992;Dec 16, 268(23):3295, 3298. View Abstract
Anonymous. Chaparral-induced toxic hepatitis: California and Texas, 1992. MMWR Morb Mortal Wkly Rep 1992;Oct 30, 41(43):812-814. View Abstract
Fleiss PM. Chaparral and liver toxicity. JAMA 9-20-1995;274(11):871-872. View Abstract
Gimeno MF, Shattner MA, Borda E, et al. Lipoxygenase inhibitors alter aggregation and adhesiveness of human blood platelets from aspirin-treated patients. Prostaglandins Leukot Med 1983;11(1):109-119. View Abstract
Gordon DW, Rosenthal G, Hart J, et al. Chaparral ingestion: the broadening spectrum of liver injury caused by herbal medications. JAMA 1995;Feb 8, 273(6):489-490. View Abstract
Heron S, Yarnell E. The safety of low-dose Larrea tridentata (DC) Coville (creosote bush or chaparral): a retrospective clinical study. J Altern Complement Med 2001;7(2):175-185. View Abstract
Ippen H. Chaparral and liver toxicity. JAMA 1995;Sep 20, 274(11):871. Author reply, 871-872. View Abstract
Kassler WJ, Blanc P, Greenblatt R. The use of medicinal herbs by human immunodeficiency virus-infected patients. Arch Intern Med 1991;151(11):2281-2288. View Abstract
Kauma H, Koskela R, Mäkisalo H, et al. Toxic acute hepatitis and hepatic fibrosis after consumption of chaparral tablets. Scand J Gastroenterol. 2004;39(11):1168-71. View Abstract
Obermeyer WR, Musser SM, Betz JM, et al. Chemical studies of phytoestrogens and related compounds in dietary supplements: flax and chaparral. Proc Soc Exp Biol Med 1995;208(1):6-12. View Abstract
Smart CR, Hogle HH, Vogel H, et al. Clinical experience with nordihydroguaiaretic acid--"chaparrel tea" in the treatment of cancer. Rocky Mt Med J 1970;67(11):39-43. View Abstract
Smith AY, Feddersen RM, Gardner KD Jr, et al. Cystic renal cell carcinoma and acquired renal cystic disease associated with consumption of chaparral tea: a case report. J Urol. 1994;152(6 Pt 1):2089-2091. View Abstract
Stickel F, Schuppan D. Herbal medicine in the treatment of liver diseases. Dig Liver Dis. 2007;39(4):293-304. View Abstract
Stickel F, Egerer G, Seitz HK. Hepatotoxicity of botanicals. Public Health Nutr 2000;Jun, 3(2):113-124. Comment in: Public Health Nutr 2000;Jun, 3(2):111. View Abstract
Woolf GM, Petrovic LM, Rojter SE, et al. Acute hepatitis associated with the Chinese herbal product jin bu huan. Ann Intern Med 11-15-1994;121(10):729-735. View Abstract
Copyright © 2013 Natural Standard (www.naturalstandard.com)
The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.
March 22, 2017