Now Flush-Free Niacin 500mg DS Niacin (vitamin B-3) is a B-complex vitamin. Flush-free Niacin contains Inositol Hexanicotinate is a form of Niacin that contains six molecules of niacin liked to a single inositol molecule. It is slowly broke down in the body to yield free niacin and inositol. This gradual release of Niacin allows for true Niacin activity without the characteristic Niacin flush that many people cannot tolerate. Recommended use: Take 1 capsule daily as needed, with a meal, or as directed by a healthcare professional. Store in a cool, dry place after opening.