Dietary Supplement. Vegetarian. Dr. Weil's exclusive immune support blend. What can you tell me about the Weil Immune Support Formula? The Weil Immune Support Formula is an exclusive combination featuring Astragalus, a tonifying herbal remedy prized in traditional Chinese medicine. This evidence-based formula also contains a potent blend of immune supportive polypore mushrooms including Maitake and Reishi. Taken on a regular basis, the unique combination of ingredients found in the Weil Immune Support Formula may support a healthy immune system. Andrew Weil, M.D., donates all his after-tax profits from the sale of Weil Nutritional Supplements to the Weil Foundation, an organization dedicated to sustaining the vision of integrative medicine. For centuries, traditional medical systems of both China and Japan have used mushrooms to increase resistance to stress and promote longevity. To enhance your immunity further, I also recommend the Chinese herbal remedy Astragalus membranaceous. You can find astragalus extract through our Vitamin Advisor as part of the General Immune Support Formula. It's safe to take every day during cold and flu season or year-round.