Thorne's Vitamin C with Flavonoids contains ascorbic acid and citrus flavonoids. The flavonoids are a mixture of naturally-occurring flavonoids, including rutin, hesperidin, and quercetin. And there is no corn starch contained in this supplement. Although ascorbic acid will work in the body without flavonoids, it works better when accompanied by flavonoid molecules, because the bioflavonoids spare vitamin C, thus providing greater antioxidant capacity.* • Immune Support* • Foundational