Astragalus has been used as an immunity booster in China for nearly 4,000 years, according to Rob McCaleb, founder of the Herb Research Foundation in Boulder, CO. Extracts from this herb can increase immune system efficiency by increasing immune activity. One study found that the extracts could increase the impaired immune function of blood cells up to and sometimes beyond normal cell ability.
According to Planetary Herbology (Lotus Press) by Michael Tierra, N.D., the herb helps strengthen digestion, raise metabolism, strengthen the immune system and promote wound healing. It can also treat chronic weakness of the lungs, shortness of breath, low energy, prolapse of internal organs, spontaneous sweating, chronic lesions and deficiency edema.
There are many, many species belonging to this family of plants. The single species used in Chinese Medicine is astragalus membranaceus also called Milk Vetch. In Chinese Medicine, the plant is usually made into a decoction by boiling the roots, removing them after boiling and then drinking the residual liquid.
According to information from the Sloan-Kettering Cancer Center, there are no known side effects from taking the herb. They also say that when it is combined with angelica, it may provide additional protective effects for the renal system. Additionally, it has been shown to reduce fatigue in athletes, inhibit tumor growth and, in certain cases, may actually improve the efficacy of certain types of chemotherapy.
Scientific studies of this herb are difficult to come by since it is usually ingested in combination with other herbs.
As a precaution, you will want to check with your physician before starting on any kind of herbal regimen - especially if you feel that your physician has done more research on herbal medicines and knows more about your body than you do.