ALL THE BENEFITS, NONE OF THE FLUSH - Niacin is called “B3” because it was the third B vitamin to be discovered. Our No Flush Niacin formula offers all the benefits you normally get in a high-quality niacin supplement, including promoting your metabolism health, supporting your cardiovascular system, as well as neurological support. However, one thing you wouldn’t experience is the flushing that can come with some vitamin B3 supplements.- Non-GMO, Gluten-Free