Nature's Sunshine Cordyceps is a fungus product that also contains the larval remains from the caterpillar larva on which it grows. Like reishi and shiitake mushrooms it strengthens the immune system. It also helps build strength and endurance. Cordyceps is used in Chinese medicine for sore and weak lower back and extremities, bleeding, wheezing, chronic cough, coughing of blood, impotence and menopause and has also has been used to benefit the glandular system in both women and men. In addition, cordyceps supports the kidneys, aids the upper respiratory tract and helps the body maintain proper blood viscosity.