Nature's Bounty Niacin Flush Free 500 mg 120 capsNature's Bounty Niacin Flush Free 500 mg 120 caps About the product: Nature's Bounty Flush Free Niacin 500 Mg Niacin, also known as Vitamin B 3, is found in foods such as beef, chicken, tuna, peanuts, avocados and potatoes. Niacin as Inositol Hexanicotinate is also known as Flush Free Niacin, which means that you don't experience an uncomfortable 'flush' when taking this product. Niacin supports energy metabolism and nervous system health.