Niacin is a B-Vitamin that your body uses in a wide variety of health functions. Rather than artificially causing changes to your system, it naturally activates your body's processes. Niacin increases the metabolism of fats and carbohydrates and assists in the functioning of the nervous and digestive systems. It also helps maintain healthy skin, is involved in liver detoxification, and aids circulation.One downside of Niacin is its tendency to cause flushing of the skin. Source Naturals' No Flush Niacin provides all of the benefits without that flushing effect by using Inositol hexanicotinate. This functions as niacin, and provides another B-vitamin Inositol.