Astragalus (Astragalus membranaceus) has been used in Traditional Chinese Medicine (TCM) for thousands of years. It was often combined with other herbs to strengthen the body against disease. Astragaus is called an adaptogen, meaning it helps protect the body against various stresses, including physical, mental, or emotional stress.
Astragalus may help protect the body from diseases such as cancer and diabetes. It contains antioxidants, which protect cells against damage. Astragalus is used to protect and support the immune system, preventing colds and upper respiratory infections, lowering blood pressure, treating diabetes, and protecting the liver.
Astragalus has antibacterial and anti-inflammatory properties. People sometimes use it on the skin for wound care. In addition, studies have shown that astragalus has antiviral properties and stimulates the immune system, suggesting that it may help prevent colds.
In the United States, researchers have looked at astragalus as a possible treatment for people whose immune systems have been weakened by chemotherapy or radiation. In these studies, astragalus supplements seem to help people recover faster and live longer. Research on using astragalus for people with AIDS has produced mixed results.
Recent research in China suggests that, because astragalus is an antioxidant, it may help people with severe forms of heart disease, relieving symptoms, lowering cholesterol levels, and improving heart function. At low-to-moderate doses, astragalus has few side effects. However, it does interact with a number of other herbs and prescription medications. Astragalus may also be a mild diuretic, meaning it helps rid the body of excess fluid.
Astragalus is a perennial plant, about 16 - 36 inches tall, that is native to the northern and eastern parts of China as well as Mongolia and Korea. It has hairy stems with leaves made up of 12 - 18 pairs of leaflets. The root is the medicinal part of the plant, and is usually harvested from 4-year-old plants.
The dried root is used medicinally.
Astragalus has been used for the following:
- Adaptogen -- protects the body from stress and disease
- Anemia -- One early study suggested astragalus may improve blood counts in people with aplastic anemia. The study was poorly designed, so more research is needed.
- Colds and influenza -- In TCM, astragalus is used as part of an herbal combination to prevent or treat colds, although TCM theory holds that, in some cases, it may make colds worse. Evidence in animal and laboratory tests suggests it may act against viruses like the ones that cause colds.
- Diabetes -- Astragalus appears to lower blood sugar. More studies are needed to determine whether it can help treat diabetes.
- Fatigue or lack of appetite from chemotherapy -- Some studies suggest astragalus may help reduce side effects from chemotherapy. The studies have not been well designed, however. More research is needed.
- Heart disease -- Several studies suggest that astragalus may act as an antioxidant and help treat heart disease. Other studies suggest astragalus may help lower cholesterol levels.
- Hepatitis -- A few studies have used a combination of herbs containing astragalus to treat hepatitis. Results have been mixed.
- Kidney disease -- Preliminary research suggests astragalus may help protect the kidneys and may help treat kidney disease. More studies are needed.
- Seasonal allergies -- One study found that astragalus may help reduce symptoms in people who have allergic rhinitis or hayfever.
Astragalus root may be available in a variety of forms:
- Tincture (liquid alcohol extract)
- Capsules and tablets, standardized and non-standardized
- Injectable forms for use in hospital or clinical settings in Asian countries
- Topically for the skin
There is not a lot of scientific evidence about giving astragalus to children, so ask your doctor first. According to TCM, you should not give astragalus to a child with fever because the herb may make the fever last longer or grow stronger. Dosage should be determined by your doctor.
Dosage depends on condition being treated, age, and weight. Work with your physician to determine the safest and most effective dosage for you. Higher doses may suppress the immune system. For best results, use a standardized astragalus supplement. Recommended doses are as follows:
- Standardized extract: 250 - 500 mg, 3 - 4 times a day standardized to 0.4% 4-hydroxy-3-methoxy isoflavone 7-sug.
- Decoction (strong boiled tea): 3 - 6 g of dried root per 12 oz water, 3 times per day
- Fluid extract (1:1) in 25% ethanol: 2 - 4 mL, 3 times a day
- Powdered root: 250 - 500 mg, 3 - 4 times per day
- Ointment: 10% astragalus applied to surface of wound. Do not apply to open wound without your doctor's supervision.
- Tincture (1:5) in 30% ethanol: 20 - 60 drops, 3 times a day
At recommended doses, astragalus has no serious side effects and can generally be used safely. It does interact with other herbs and medications (see Possible Interactions section).
Evidence about whether astragalus is safe for women who are breastfeeding or nursing is lacking. Talk to your doctor before taking any medication, including herbs.
People with autoimmune disease should speak with their doctor first before taking Astagalus because it may stimulate the immune system.
Many practitioners recommend against using any single "adaptogenic" herbs over long periods of time. Instead, they might suggest rotating among several "adaptogens" every couple of months.
If you take any of the following medications, you should not use astragalus without first asking your doctor:
Drugs that suppress the immune system -- Astragalus may interfere with these drugs. If you have an autoimmune disease such as rheumatoid arthritis or lupus, or take cyclophosphamide, a medication used to reduce the chances of rejection in transplant recipients, or corticosteroids, do not take astragalus.
Lithium -- Astragalus can make it harder for the body to get rid of lithium, so dangerously high levels of the drug could build up.
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