Different substances can irritate the sinuses and impact histamine production and release. Life Seasons Breathe-X helps the body maintain histamine production and inflammation within the normal range and supports the body’s natural immune function.Breathe-X contains quercetin and citrus bioflavonoids, which support the body by increasing its resistance to allergic response. These flavonoids remove excess allergy-activated immune cells while leaving the vast bulk of responder cells to fight off bacteria and other foreign invaders.- Does not contain artificial colors, gluten, preservatives, yeast, wheat, soy, corn and milk- Vegetarian- Quercetin, Bromelain, Vitamin C, Citrus Bioflavanoids, and Nettle Leaf.