Histamine Relief includes quercetin, a powerful flavonoid, to support healthy histamine levels. Bromelain enhances the absorption of quercetin and supports mucosal tissue health. Stinging nettles leaf extracts balance a hyper-immune response. N-acetyl cysteine clears the airways by promoting normal viscosity of mucus. This powerful combination actively promotes healthy nasal and sinus passages for individuals with elevated histamine and respiratory irritation. Vitamin C has many immune boosting properties, but is distinctively beneficial for individuals with seasonal discomfort because of its ability to deactivate histamine.