Effective for the immune system. Studies have shown that Astragalus stimulated T-cell activity and restores immune function in cancer patients with impaired immune systems. It has been also noted that it increased the number of stem cells (the ‘generic’ cells that can become any type needed) in the marrow and lymph tissue. Researchers at the University of Texas Medical Center found that Astragalus was able to completely restore the function of cancer patients’ compromised immune cells. Astragalus protects the liver.