Its immunostimulant, antibacterial, antiviral, anti- inflammatory, adaptogenic, and diuretic effects. It also improves stamina. No single compound is responsible for its wideranging, effects, though polysaccharides are involved in immunostimulant activity.

Sometimes called milk vetch root, huang qi, or locoweed, this member of the legume family is a powerful healing root. Its sweet taste reveals its moisture bringing ability to enhance the immune system. A great additive to chicken soup, it is an ideal herb to use to ward off the colds and flu of loved ones, students, or co-workers. It can be great with skin problems, poor immunity, a tendency to lung problems, and a host of other issues. After heart surgery this can improve circulation.
Astragalus is best taken after it has had a chance to simmer in a pot for twenty minutes or more. The liquid is drunk (or eaten in chicken soup), and the herb thrown away. This can be taken one cup at a time a few times a day, unless chemotherapy is being under gone. That would increase the dosage considerably, and seeing an herbalist for appropriate dosage would be important.

Caution should be taken with patients receiving immunosuppressive therapy, such as transplant patients, or patients with autoimmune diseases. The selenium present in astragalus can lead to selenium poisoning in excessive use. May increase bleeding in the event of injury. Should not be taken in the presence of a fever.

In the early 1980s, researchers in Houston, Texas, studied the effects of astragalus on nineteen cancer patients and fifteen healthy individuals. A chemical fraction extract of astragalus was found to restore T-cell function in 90 percent of the cancer patients to levels observed in the healthy subjects. The studies showed that astragalus had a strong immunostimulant effect, thus establishing a basis for using it to improve response in cancer patients. Chinese studies show that immunostimulant effects include enhancing the particle ingestion capacity of white blood cells.