Astragalus membranaceus or milk vetch has been used in Chinese medicine for over 2,000 years to strengthen the immune and respiratory systems and to fight the flu. Astragalus belongs to a class of herbs called adaptogens, and helps the body handle stress. Astragalus also fights pathogens like bacteria and viruses.
Dosage: one dropper of tincture of Astragalus (standardized to 15 percent polysaccharides) to a hot liquid like tea or soup three times a day. As tablets, take 350 to 400 milligrams three times a day.