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Astragalus (Astragalus membranaceus)
Generic Name: Locoweeds
CategoryHerbs & Supplements
Astragalus gummifera, Astragalus lentiginosus, Astragalus mollissimus, Astragalus mongholicus, Astragalus trigonus, astragel, baak kei, beg kei, bei qi, buck qi, Fabacea (family), goat's horn, goat's thorn, green dragon, gum dragon, gum tragacanthae, gummi tragacanthae, hoang ky, hog gum, huang-chi, Huang Qi, huangoi, huangqi, hwanggi, ji cao, Leguminosae (family), locoweed, membranous milk vetch, milk vetch, Mongolian milk, Mongolian milk vetch, neimeng hhuangqi, ogi, ougi, radix astragali, spino santo, Syrian tragacanth, tai shen, tragacanth, wong kei, yellow vetch, Zhongfengnaomitong.
Astragalus products are derived from the roots of Astragalus membranaceus or related species, which are native to China. In traditional Chinese medicine, astragalus is commonly found in mixtures with other herbs, and is used in the treatment of numerous ailments, including heart, liver, and kidney diseases, as well as cancer, viral infections, and immune system disorders. Western herbalists began using astragalus in the 1800s as an ingredient in various tonics. The use of astragalus became popular in the 1980s based on theories about anti-cancer properties, although these proposed effects have not been clearly demonstrated in reliable human studies.
Some medicinal uses of astragalus are based on its proposed immune stimulatory properties, reported in preliminary laboratory and animal experiments, but not conclusively demonstrated in humans. Most astragalus research has been conducted in China, and has not been well designed or reported.
EvidenceDISCLAIMER: 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.
Few clinical trials have investigated the effects of astragalus alone in athletes. Further research is needed before a clinical recommendation can be made.
Few clinical trials have investigated astragalus in burn patients. Further research is required before a clinical recommendation can be made.
A small amount of research suggests that astragalus may enhance the effectiveness of conventional treatments for cancer, such as chemotherapy and radiation. Astragalus may also lessen the degree of side effects experienced with cancer treatments and improve quality of life. Better studies are needed in this area before a firm conclusion can be reached.
Several small studies suggest astragalus may help improve heart function in individuals with chest pain, a history of heart attack, or a history of congestive heart failure. However, larger studies are needed to determine the exact benefit and safety of astragalus for these conditions.
Chemotherapy side effects:
In Chinese medicine, astragalus-containing herbal mixtures are sometimes used with the intention to reduce side effects of cancer treatments. Due to a lack of well-designed research, a firm conclusion cannot be drawn.
Coronary artery disease:
In Chinese medicine, herbal mixtures containing astragalus have been used to treat heart diseases. High quality human research is necessary before a conclusion can be drawn.
There is some evidence that astragalus can improve the effectiveness of conventional diabetes therapies. More research is required in this field before recommendations can be made.
There is some evidence that astragalus may offer symptomatic improvement for chronic heart failure. Recommendations cannot be made until well-designed clinical trials have been conducted.
Research suggests that astragalus may have anti-hepatitis effects. Additional study is needed in this area.
Antiviral effects have been reported in early studies. Additional studies are warranted.
Several small studies report that astragalus may stimulate and improve immune system function in conditions such as the common cold, blood disorders, cancer, and HIV/AIDS. Further research is needed in this area.
One clinical trial suggests that astragalus may aid in mental performance of children with low IQ. Further, well-designed clinical trials are required before recommendations can be made.
Myocarditis/endocarditis (heart infections):
Several studies suggest that astragalus may improve symptoms of viral myocarditis. However, these studies are small and poorly designed. Larger, higher quality studies are needed in this area.
Astragalus has been used traditionally to aid in smoking cessation. Well-designed clinical trials are required before recommendations can be made.
One clinical trial suggests the potential for benefit of astragalus in patients with tuberculosis. Further well-designed clinical trials are required before recommendations can be made.
Upper respiratory tract infection:
Astragalus is often used in Chinese medicine as a part of herbal mixtures to prevent or treat upper respiratory tract infections. Due to a lack of well-designed research, no firm conclusions can be drawn.
TraditionWARNING: DISCLAIMER: The below uses are based on tradition, scientific theories, or limited research. 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. There may be other proposed uses that are not listed below.
Adults (over 18 years old)
In Chinese medicine, astragalus is used in soups, teas, extracts, and pills. In practice and in most scientific studies, astragalus is one component of multi-herb mixtures. Therefore, precise dosing of astragalus alone is not clear. Safety and effectiveness are not clearly established for any particular dose. Various doses of astragalus have been used or studied, including 250 to 500 milligrams of extract taken four times daily; 1 to 30 grams of dried root taken daily (doses as high as 60 grams have been reported); or 500 to 1,000 milligrams of root capsules taken three times daily. Dosing of tinctures or fluid extracts depends on the strength of the preparations. A tincture dose (1:5) of 3-6 milliliters three times daily by mouth, or 15 to 30 drops twice daily by mouth has been used. Note that tinctures may have high alcohol content.
For herpes simplex keratitis, 0.5 milliliters astragalus (1:1 extract) for three weeks has been used on the skin. For wound healing, a 10% astragalus ointment has been applied to wound surfaces. The maximum level used is 1.3% when used topically in lotions, denture creams, toothpaste,s and cosmetics, according to secondary sources
For non-small cell lung cancer, 60 milliliters has been given intraveneously per day. Injections should only be given under the supervision of a qualified healthcare professional.
Note: In theory, consumption of the tragacanth (gummy sap derived from astragalus) may reduce the absorption of drugs taken by mouth, and they should be taken at separate times.
Children (younger than 18 years)
There is not enough scientific data to recommend astragalus for children.
SafetyDISCLAIMER: Many complementary techniques are practiced by healthcare professionals with formal training, in accordance with the standards of national organizations. However, this is not universally the case, and adverse effects are possible. Due to limited research, in some cases only limited safety information is available.
In theory, patients with allergies to members of the Leguminosae (pea) family may react to astragalus. Cross-reactivity with quillaja bark (soapbark) has been reported for astragalus gum tragacanth.
Side Effects and Warnings
Some species of astragalus have caused poisoning in livestock, although these types are usually not used in human preparations (which primarily include Astragalus membranaceus). Livestock toxicity, referred to as "locoweed" poisoning, has occurred with species that contain swainsonine (Astragalus lentiginosus, Astragalus mollissimus, Astragalus nothrosys, Astragalus pubentissimus, Astragalus thuseri, Astragalus wootoni), or in species that accumulate selenium (Astragalus bisulcatus, Astragalus flavus, Astragalus praelongus, Astragalus saurinus, Astragalus tenellus). Ingestion of certain toxic astragalus plants may cause neurological syndromes, some of which are irreversible.
Overall, it is difficult to determine the side effects or toxicity of astragalus because astragalus is most commonly used in combination with other herbs. There are numerous reports of side effects ranging from mild to deadly in the U.S. Food and Drug Administration (FDA) computer database, although most of these are with multi-ingredient products and they cannot be attributed to astragalus specifically. Side effects reported in people using combination products that contain astragalus include heart palpitations, abdominal discomfort, diarrhea, and aspiration pneumonia.
Astragalus used alone and in recommended doses is traditionally considered to be safe, although safety is not well studied. The most common side effects appear to be mild stomach upset and allergic reactions. In the United States, tragacanth (astragalus gummy sap) has been classified as GRAS (generally recognized as safe) for food use, but astragalus does not have GRAS status.
Based on preliminary animal studies and limited human research, astragalus may decrease 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 may need to be monitored by a healthcare professional, and medication adjustments may be necessary.
Based on anecdotal reports and preliminary laboratory research, astragalus may increase the risk of bleeding. Caution is advised in patients with bleeding disorders or taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary.
Preliminary reports of human use in China have noted decreased blood pressure at lower doses and increased blood pressure at higher doses. Animal research suggests possible blood pressure-lowering effects. Due to a lack of well-designed studies, no firm conclusions can be drawn. Nonetheless, people with abnormal blood pressure or taking blood pressure medications should use caution and be monitored by a qualified healthcare professional. Palpitations have been noted in human reports in China.
Based on animal study, astragalus may act as a diuretic and increase urination. In theory, this may lead to dehydration or metabolic abnormalities. There is one report of pneumonia in an infant after breathing in an herbal medicine powder including Astragalus sarcocolla.
Because astragalus may stimulate the immune system, individuals with autoimmune diseases or organ transplants should consult a healthcare professional before starting therapy. Astragalus is not recommended for people with acute inflammation or acute illness with fever.
Astragalus may increase growth hormone levels.
Pregnancy and Breastfeeding
Many tinctures contain high levels of alcohol and should be avoided during pregnancy.
Interactions with Drugs
Based on preliminary animal studies and limited human research, astragalus may decrease blood sugar levels. Caution is advised in patients with diabetes or hypoglycemia and in those taking drugs that affect blood sugar. Serum glucose levels may need to be monitored by a healthcare provider, and medication adjustments may be necessary.
Preliminary reports of human use in China have noted decreased blood pressure at lower doses and increased blood pressure at higher doses. Animal research suggests possible blood pressure-lowering effects. Although well-designed studies are not available, people taking drugs that affect blood pressure should use caution and be monitored by a qualified healthcare professional. It has been suggested that beta-blocker drugs such as propranolol (Inderal®) or atenolol (Tenormin®) may reduce the effects on the heart of astragalus, although this has not been well studied.
Based on anecdotal reports, astragalus may increase the risk of bleeding when taken with drugs that 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 and traditional use, astragalus may act as a diuretic and increase urination. In theory, this may lead to dehydration or metabolic abnormalities (low blood sodium or potassium), particularly when used in combination with diuretic drugs such as furosemide (Lasix®), chlorothiazide (Diuril®), or spironolactone (Aldactone®).
Based on laboratory and animal studies, astragalus may possess immune stimulating properties, although research in humans is not conclusive. Some research suggests that astragalus may interfere with the effects of drugs that suppress the immune system, such as steroids or agents used in organ transplants. Better research is necessary before a firm conclusion can be reached.
Some sources suggest other potential drug interactions, although there is no reliable scientific evidence in these areas. These include reduced effects of astragalus when used with sedative agents such as phenobarbital or hypnotic agents like chloral hydrate; increased effects of astragalus when taken with colchicine; increased effects of paralytics such as pancuronium or succinylcholine when used with astragalus; increased effects of stimulants such as ephedrine or epinephrine; increased side effects of dopamine antagonists such as haloperidol (Haldol®); and increased side effects of the cancer drug procarbazine.
In theory, consumption of the tragacanth (gummy sap derived from astragalus) may reduce absorption of drugs taken by mouth, and should be taken at separate times.
Based on human study, activity of recombinant interferon 1 may be potentiated by astragalus.
Astragalus may also interact with antibiotics.
Interactions with Herbs and Dietary Supplements
Based on preliminary animal studies and limited human research, astragalus may decrease blood sugar levels. Caution is advised in patients with diabetes or hypoglycemia, and in those taking herbs or supplements that affect blood sugar. People using other herbs or supplements that may alter blood sugar levels, should be monitored closely by a healthcare professional while using astragalus. Dosing adjustments may be necessary.
Preliminary reports of human use in China have noted decreased blood pressure at lower doses and increased blood pressure at higher doses. Animal research suggests possible blood pressure-lowering effects. Although well-designed studies are not available, people taking herbs or supplements that affect blood pressure should use caution and be monitored by a qualified healthcare professional.
Based on anecdotal reports, astragalus may increase the risk of bleeding when taken with herbs or supplements that increase the risk of bleeding. Examples include Ginkgo biloba and garlic (Allium sativum).
Based on animal research and traditional use, astragalus may act as a diuretic and increase urination. In theory, this may lead to dehydration or metabolic abnormalities (low blood sodium or potassium), particularly when used in combination with herbs or supplements that may possess diuretic properties.
Based on laboratory and animal studies, astragalus may possess immune stimulating properties, although research in humans is not conclusive. It is not known if astragalus interacts with other agents that are proposed to affect the immune system.
In theory, consumption of tragacanth (gummy sap derived from astragalus) may reduce the absorption of herbs or supplements taken by mouth, and should be taken at separate times.
Activity of lipid lowering (cholesterol lowering) herbs may be potentiated.
This information is based on a professional level monograph edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com): Ethan Basch, MD, MSc, MPhil (Memorial Sloan-Kettering Cancer Center); Wendy Chao, PhD (Natural Standard Research Collaboration); Dawn Costa, BA, BS (Natural Standard Research Collaboration); Paul Hammerness, MD (Massachusetts General Hospital); Shaina Tanguay-Colucci, BS (Natural Standard Research Collaboration); Catherine Ulbricht, PharmD (Massachusetts General Hospital); Mamta Vora, PharmD (Northeastern University); Wendy Weissner, BA (Natural Standard Research Collaboration).
BibliographyDISCLAIMER: 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.
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Weng XS. [Treatment of leucopenia with pure Astragalus preparation--an analysis of 115 leucopenic cases]. Zhongguo Zhong Xi Yi Jie He Za Zhi 1995;15(8):462-464.
Wu XS, Chen HY, Li M. [Clinical observation on effect of combined use of Astragalus and compound salviae injection in treating acute cerebral infarction]. Zhongguo Zhong Xi Yi Jie He Za Zhi 2003;23(5):380-381.
Yin X, Zhang S, Kong Y, et al. Observation on efficiency of jiangtang capsule in treating diabetes mellitus type 2 with hyperlipidemia. Chinese Journal of Integrated Traditional and Western Medicine 2001;7(3):214-216.
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Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.