Thumbnail sketch: Nicotinic acid works by reducing LDL (“bad”) cholesterol and triglycerides and increasing HDL (“good”) cholesterol. Niaspan contains niacin, also called nicotinic acid, a B vitamin (vitamin B3). It occurs naturally in plants and animals and is present in many multiple vitamin supplements.Nicotinic acid is used to lower cholesterol and triglycerides (types of fat) in the blood. It is also used to lower the risk of heart attack in people with high cholesterol who have already had a heart attack. It is sometimes used to treat coronary artery disease (also called atherosclerosis).