- Balanced Immune System - Supports Healthy Seasonal Immune Function - A Dietary Supplement - Non-GMO - Vegetarian - Vegan - Kosher - General Health Family Owned Since 1968 GMP Quality Assured Quercetin is a naturally occurring free radical scavenger that supports healthy seasonal immune system function. Laboratory studies have demonstrated that quercetin can also help to promote normal respiratory function. Bromelain has a long history of use by herbalists and is known to help support a balanced immune system response to environmental challenges. This complementary combination may thus promote year-round respiratory health and support overall seasonal comfort.