Astragalus contains numerous components, including flavonoids, polysaccharides, triterpene glycosides (e.g., astragalosides I-VII), amino acids, and trace minerals.12 Several preliminary clinical trials in China have suggested that astragalus can benefit immune function and improve survival in some people with cancer.13 Given the poor quality of these trials, it is difficult to know how useful astragalus really was. One Chinese trial also found that astragalus could decrease overactive immune function in people with systemic lupus erythematosus (SLE), an autoimmune disease.14 Further trials are needed, however, to know if astragalus is safe for people with SLE, or any other autoimmune disease.
A double-blind trial found that, in people undergoing dialysis for kidney failure, intravenous astragalus improved one facet of immune function compared to the immune function of untreated people.15 Further study is needed to determine if astragalus can help prevent infections in people undergoing dialysis. Early clinical trials in China suggest astragalus root might also benefit people with chronic viral hepatitis, though it may take one to two months to see results.16
In preliminary trials in China, astragalus has been used after people suffer heart attacks.17 More research is needed to determine whether astragalus is truly beneficial in this situation.