Niacin, also known as nicotinic acid and vitamin B3, is a water soluble, essential B vitamin that, when given in high doses, is effective in lowering low density lipoprotein (LDL) cholesterol and raising high density lipoprotein (HDL) cholesterol, which makes this agent of unique value in the therapy of dyslipidemia. Niacin can cause mild-to-moderate serum aminotransferase elevations and high doses and certain formulations of niacin have been linked to clinically apparent, acute liver injury which can be severe as well as fatal.

Nicotinic acid is available in three commercial grades: food grade, feed grade and pharmaceutical grade.It is mainly used as a nutritional additive (water-soluble vitamin) in feed, and also as an intermediate for food, pharmaceuticals and dyestuffs.It is also used as an additive in electroplating solutions and as a biochemical reagent.