Overview:

Astragalus (Astragalus membranaceus) has been used in Traditional Chinese Medicine for thousands of years, often in combination with other herbs, to strengthen the body against disease. Astragaus is an adaptoge, 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 caused by free radicals, byproducts of cellular energy. Astragalus is used to protect and support the immune system, for preventing colds and upper respiratory infections, to lower blood pressure, to treat diabetes, and to protect the liver.

Astragalus has antibacterial, and anti-inflammatory properties. It is sometimes used topically for wounds. In addition, studies have shown that astragalus has antiviral properties and stimulates the immune system, suggesting that it is indeed effective at preventing colds.

In the United States, researchers have investigated astragalus as a possible treatment for people whose immune systems have been compromised by chemotherapy or radiation. In these studies, astragalus supplements have been shown to speed recovery and extend life expectancy. Research on using astragalus for people with AIDS has produced inconclusive results.

Recent research in China indicates that astragalus may offer antioxidant benefits to people with severe forms of heart disease, relieving symptoms and improving heart function. At low-to-moderate doses, astragalus has few side effects, although it does interact with a number of other herbs and prescription medications. Astragalus may also have mild diuretic (rids the body of excess fluid) activity.

Plant Description:

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, and is usually harvested from 4-year-old plants.

Parts Used:

The dried root is used medicinally.

Medicinal Uses and Indications:

Traditional uses include the treatment of the following:

• Adaptogen - protects the body from stress
• Colds and influenza
• Persistent infection
• Fever
• Multiple allergies
• Asthma
• Chronic fatigue
• Fatigue or lack of appetite associated with chemotherapy
• Anemia
• Wounds
• Heart disease
• Kidney disease
• Hepatitis
• Stomach ulcers

It is also used to treat general digestive disturbances, including diarrhea, gas, and bloating.

Available Forms:

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

How to Take It:

Pediatric

Astragalus may be given to children to support the immune system. A child with fever, however, should not be given astragalus because, according to Traditional Chinese Medicine, the herb may make the fever last longer or grow stronger. The dose should be determined by adjusting the recommended adult dose to account for the child's weight. Most herbal dosages for adults are calculated on the basis of a 150 lb (70 kg) adult. Therefore, if the child weighs 50 lb (20 - 25 kg), the appropriate dose of astragalus would be 1/3 of the adult dosage. However, because strengths and concentrations will vary with different preparations, dosages should be determined on an individual basis. Any long-term dosage should be determined by your doctor.

Adult

Doses from 1 - 25 g per day are sometimes used. Higher doses may suppress the immune system. For best results, it is recommended to use a standardized astragalus supplement. Recommended doses are as follows:

• Standardized extract: 250 - 500 mg, three to four 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, three times per day
• Fluid extract (1:1) in 25% ethanol: 2 - 4 mL, three times a day
• Powdered root: 500 - 1,000 mg, three or four 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: 3 - 5 mL, three times a day

Precautions:

At recommended doses, astragalus has no serious side effects and can generally be used safely. It does interact with other herbs and medications (seePossible Interactions section).

If you are pregnant or breast-feeding, you should talk to your doctor before taking any medication, including herbs.

Possible Interactions:

If you are being treated with any of the following medications, you should not use astragalus without first talking to your health care provider:

Drugs that suppress the immune system -- Astragalus may counteract the immune-suppressing effects of cyclophosphamide, a medication used to reduce the chances of rejection in transplant recipients, as well as corticosteroids.

Alternative Names:

Astragalus membranaceus; Astragalus mongholicus; Huang-qi; Milk-vetch root