Flush Free Niacin 500 mg, 180 Vcaps, NOW FoodsNOW Foods Flush Free Niacin 500 mg Dietary Supplement. Double Strength. Nutritional Health. Vegetarian Formula. Niacin (Vitamin B 3) is an essential B vitamin necessary for good health. Many Niacin supplements cause a temporary Niacin flush or tingling red rash on the skin when taken in large doses. This flush free Niacin is formulated to avoid such reactions. Supplement Facts Serving Size: 1 Vcap Servings Per Container: 180 Amount Per Serving % Daily