Niacin lowers blood triglycerides and raises high density lipoproteins. It also however provokes a burning flush sensation which is not comfortable. that the mechanism is meaited through the G-protein coupled pathway GPR109A. When niacin comes into contact with the G-protein coupled pathway GPR109A, a protein Β-arrestin 1 comes to the recptor which results in the expression of arachidonate which causes the flushing. Walters et al ( 2009) beta-Arrestin1 mediates nicotinic acid-induced flushing, but not its antilipolytic effect, in mice. J Clin Invest.vol 119(5):pp 1312-21.