Bile acid sequestrants, fibric acid derivatives (fibrates), hydroxy-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors ("statins"), and niacin are able to increase HDL-C serum concentrations to varying degrees. Bile acid sequestrants are the least effective, whereas niacin is the most powerful agent for increasing HDL-C levels. Because of 2 alternate metabolic pathways of niacin breakdown, flushing or hepatotoxicity can occur in patients taking niacin. These effects can be mediated in a carefully designed formulation of niacin that releases the drug at a predictable rate. Niacin has few drug interactions and is a relatively inexpensive means of increasing HDL-C. A combination formulation that combines niacin plus a statin has shown promise in ongoing clinical trials.