NOW® Immune Renew™ is a healthy immune system supporting formulation containing Standardized Astragalus Extract and a High Beta-Glucan Proprietary Mushroom Blend. Astragalus has been shown in non-clinical studies to support a number of aspects of healthy immune function, including the enhancement of T-Cell and Natural Killer Cell activity. Natural killer cells are so named because they destroy unhealthy cells in the body virtually on contact. NOW's Proprietary Blend of eight organic mushrooms provides additional healthy immune support due to its high 1,3 Beta Glucan content. 1,3 Beta Glucans are especially valuable to healthy immune system response, though they're increasingly lacking in today's typical diet. Scientific studies have demonstrated that the 1,3 form of Beta Glucan found in mushrooms possesses remarkable abilities to support both innate and adaptive healthy immune function. A healthy immune system is the foundation of good health.