Quercetin is a bioflavonoid that supports cellular health and function. In human cell culture studies, it has been shown to block the manufacture and release of inflammation-causing substances,153,154 which can help support a healthy immune response to the seasonally changing environment. It also helps promote a healthy cardiovascular system by preserving endothelial integrity155 and supporting healthy blood glucose levels for those already within normal range.156 Optimized Quercetin is a proprietary formulation that sets the “gold standard” for high-quality quercetin derived from a food-source blend.