High-density lipoprotein (HDL) cholesterol is known as the "good" cholesterol because it helps remove other forms of cholesterol from your bloodstream. Higher levels of HDL cholesterol are associated with a lower risk of heart disease. Cholesterol is a waxy substance that's found in all of your cells and has several useful functions, including helping to build your body's cells. It's carried through your bloodstream attached to proteins. These proteins are called lipoproteins. Lifestyle changes known to increase HDL, such as moving more, quitting smoking or improving your diet, have been shown to lower the risk of heart attacks, However, medications that specifically increase HDL levels have failed to reduce the rate of heart attacks. HDL levels are sometimes improved by drugs used to lower LDL and triglyceride levels — such as prescription niacin; fibrates such as gemfibrozil (Lopid); and certain statins, particularly simvastatin (Zocor) and rosuvastatin (Crestor). But clinical trials for several drugs specifically designed to increase HDL levels were halted early because they didn't reduce the risk of heart attacks. Drugs containing testosterone and other anabolic steroids can lower your HDL cholesterol levels. Avoiding these drugs may help increase your HDL numbers.