This drug works in the liver by affecting the production of blood fats. Niacin is prescribed to lower triglycerides and LDL cholesterol and raise HDL (“good”) cholesterol.

Niacin side effects may include flushing, itching and stomach upset. Your liver functions may be closely monitored, as niacin can cause toxicity. Nonprescription immediate release forms of niacin usually have the most side effects, especially at higher doses. Niacin is used cautiously in diabetic patients as it can raise blood sugar levels.

Niacin comes in prescription form and as “dietary supplements.” Dietary supplement niacin must  not be used as a substitute for prescription niacin. It should not be used for lowering cholesterol because of potential serious side effects. Dietary supplement niacin is not regulated by the U.S. Food and Drug Administration (FDA) the same way that prescription niacin is. It may contain widely variable amounts of niacin — from none to much more than the label states. The amount of niacin may even vary from lot to lot of the same brand. Consult your doctor before starting any niacin therapy.

Niacin was involved with a study, the ARBITER 6–HALTS trial that I commented on in a blog.