Niacin is not typically prescribed for high blood pressure. It is used to reduce the bad cholesterol, LDL, and increase the good cholesterol, HDL, within a person's blood.
Niacin is a medication that is used to treat high cholesterol or high lipid levels in the blood. It is not a medication used to treat hypertension. Treating hyperlipidemia is important because it decreases risk for heart attack and stroke.