Astragalus is an adaptogen, it protects the body from stress and disease. One early study suggested astragalus may improve blood counts in people with aplastic anemia. In TCM, astragalus is used as part of an herbal combination to prevent or treat colds. Astragalus appears to lower blood sugar. Some studies suggest astragalus may help reduce side effects from chemotherapy. Several studies suggest that astragalus may act as an antioxidant and help treat heart disease. Other studies suggest astragalus may help lower cholesterol levels. A few studies have used a combination of herbs containing astragalus to treat hepatitis. Preliminary research suggests astragalus may help protect the kidneys and may help treat kidney disease. One study found that astragalus may help reduce symptoms in people who have allergic rhinitis or hayfever.