Chaparral and Nordihydroguaiaretic Acid

by MedlinePlus

Chaparral and its constituent nordihydroguaiaretic acid (NDGA) have been reported to possess antioxidant/free-radical scavenging properties. Although proposed as a treatment for cancer, effectiveness has not been demonstrated in clinical trials. Chaparral or NDGA has been associated with cases of hepatitis, cirrhosis, liver failure, renal cysts, and renal cell carcinoma. In response to these reports, the U.S. Food and Drug Administration 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.

Synonyms

Chaparral taxa, chaparral tea, chaparro, creosote bush, creosote, dwarf evergreen oak, el gobernadora, falsa alcaparra, geroop, obernadora, greasewood, guamis, gumis, hediondilla, hideonodo, jarillo, kovanau, kreosotstrauch, larrea, Larrea divaricata, Larrea glutiosa , Larrea mexicana, Larrea mexicana Moric, Larrea tridentate, palo ondo, shoegoi, sonora covillea, tasago, ya-tmep, yah-temp, zygophyllaceae.

Evidence

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.

Uses based on scientific evidence

Cancer

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 associated 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.

Uses based on tradition or theory

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 healthcare provider.

Abdominal cramps, abortion, abortifacient, acne, actinic keratosis, allergies, antibacterial, anti-inflammatory, antioxidant, anti-parasitic, antiseptic, anti-tumor, antiviral, arthritis, immune system disorders, "blood purifier," bowel cramps, breast cancer, breathing problems, bronchitis, bruises, burns, bursitis, cancer, cavity prevention (mouthwash), chicken pox, central nervous system disorders, cold sores, colds, coughs, chronic skin disorders, cytomegalovirus, cytotoxic, dandruff, decomposition, diabetes, diarrhea, dietary supplement, diuretic (increasing urine flow), flu, food additive, dysentery, dysmenorrheal, enteritis, Epstein-Barr virus, ethanol withdrawal, fertility, gas, gastrointestinal disorders, hair tonic, hallucinations (including due to "LSD" ingestion), heartburn, herpes simplex virus, herpes zoster virus, hypoglycemic, immune function stimulation, impetigo, indigestion, influenza, inhibitory effects, intestinal problems, Kaposi's sarcoma, leukemia, liver cleanser, liver metabolic function, melanoma, menstrual cramps, neuritis, ovarian cancer, painful joints, pain, parasites, poultice, premenstrual syndrome, psoriasis, rancidity, respiratory tract infections, respiratory, rheumatic diseases, sciatica, scratches, skin disorders, skin infections, snakebite pain, stomach ulcer, tuberculosis, type 2 diabetes, urinary tract infections, venereal disease, vomiting, wound healing.

Dosing

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.

Standardization

Standardization involves measuring the amount of certain chemicals in products to try to make different preparations similar to each other. It is not always known if the chemicals being measured are the "active" ingredients. There is no widely accepted standardization for chaparral.

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, 1-3 cups daily 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.

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 suggested, 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.

Safety

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.

Allergies

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. Exposure to lignans, which may yield toxicity, appears to be greater from capsule or tablets than from decoctions of chaparral tea. The FDA removed chaparral from the "generally recognized as safe" (GRAS) list in 1970, and considers chaparral to be unsafe. Elevations of liver enzymes or 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.

Pregnancy & Breastfeeding

There is not enough scientific evidence to support the safe use of any dose of chaparral during pregnancy or breastfeeding.

Chaparral may inhibit ovulation and decrease the chance that women will become pregnant.

About the Author

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