A customized formulation of Ester-C with bioflavonoids. Ester-C is a patented nutritional product that contains ascorbic acid and calcium. This formulation is non-acidic and minimally irritating to the intestines. Esterol also provides 3 types of bioflavonoids - quercetin, rutin, and proanthocyanidins from grape seed extract. Ester-C vitamin C is corn-source. Serving Size: 1Vegetable Capsule Servings Per Container: 100 Amount Per Serving % Daily Value Vitamin C (as calcium ascorbate) 1.35 g 1500%Calcium (as calcium ascorbate) 150 mg 12%Rutin 100 mgQuercetin 50 mgGrape Seed Extract (92% Proanthocyanidins) 5 mg Other Ingredients: Hydroxypropyl methylcellulose, magnesium stearate, silicon dioxideAs a dietary supplement, 1 or 2 capsules one or two times daily between meals, or as directed by a healthcare practitioner.Variations in product color may occur. Keep in a cool, dry place, tightly capped.