Cycloastragenol (Cycloastragenol), is the dry root of Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao of leguminous plants. It belongs to triterpenoid saponins and is mainly obtained by the hydrolysis of Astragaloside IV. Cycloastradiol is the only telomerase activator discovered so far, which delays telomere shortening by increasing telomerase.