NOW Foods Quercetine with Bromelain 120 vcaps Quercetin is a naturally occurring bioflavonoid that supports healthy histamine levels, thereby helping to sustain a balanced immune response. Bromelain, an enzyme derived from pineapple stems, also supports healthy immune system function. The combination of Quercetin & Bromelain therefore provides powerful immunomodulating benefits important for the management of occasional seasonal discomfort.*