Mayo Clinic Health Library

Niacin to boost your HDL, 'good,' cholesterol

Updated: 06-03-2011

Niacin, a B vitamin, has long been used to increase high-density lipoprotein (HDL), or the "good," cholesterol. HDL cholesterol helps sweep up low-density lipoprotein (LDL), or the "bad," cholesterol, in your bloodstream. Although niacin is readily available and effective, it hasn't gotten much attention compared to other cholesterol drugs.

Most discussion about cholesterol focuses on lowering your low-density lipoprotein (LDL), or "bad," cholesterol. That's still an important goal. But boosting your HDL level can be just as important as lowering your LDL cholesterol. Taking niacin — either by itself or along with other cholesterol-lowering medication — may help control your total cholesterol level.

What is niacin?

Niacin (nicotinic acid) is a B vitamin that's used by your body to turn carbohydrates into energy. Niacin also helps keep your nervous system, digestive system, skin, hair and eyes healthy. That's why niacin is often a part of a daily multivitamin, though most people get enough niacin from the food they eat.

You may see niacin labeled in different ways. As part of a multivitamin or supplement, it's often just referred to as niacin. When it's used as a treatment to increase your HDL cholesterol or correct a niacin deficiency, it's sold in higher doses that are prescribed by your doctor. It's not possible to get enough niacin from the food you eat to increase your HDL cholesterol. Some common brand names of prescription niacin include:

  • Niaspan
  • Niacor

Niacin is also available as an over-the-counter (OTC) supplement. However, don't take niacin — even in the over-the-counter form — without discussing it with your doctor first because niacin can cause side effects when taken in high doses.

What impact does niacin have on cholesterol?

Niacin can raise HDL cholesterol — the "good" cholesterol — by 15 to 35 percent. This makes niacin the most effective drug available for raising HDL cholesterol. While niacin's effect on HDL is of most interest, it's worth noting that niacin also decreases your LDL and triglyceride levels. High levels of LDL and triglycerides are significant risk factors for heart disease.

You may have heard that a large study that examined the effect of niacin to raise HDL cholesterol was stopped early. This study examined how niacin worked when used with statin medications for people who have a history of heart disease. The trial was stopped because no difference was seen between people who took prescription-strength niacin and people who took a placebo. The study also found there may be a small increase in the risk of stroke for people who take niacin to increase their HDL cholesterol level. More research is necessary to see how effective niacin might be compared with other heart disease medications. You shouldn't stop taking niacin unless you get your doctor's OK. Talk to your doctor if you're concerned about taking niacin.

Why is having a high HDL cholesterol level important?

HDL, or "good," cholesterol picks up excess bad cholesterol in your blood and takes it back to your liver for disposal. The higher your HDL cholesterol, the less bad cholesterol you'll have in your blood.

Cholesterol levels are measured in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L):

  • For men, HDL levels under 40 mg/dL or 1 mmol/L increase the risk of heart disease.
  • For women, HDL levels under 50 mg/dL or 1.3 mmol/L increase the risk of heart disease.
  • An HDL level above 60 mg/dL or 1.6 mmol/L is considered ideal for men or women.

Having a low HDL level by itself is a risk factor for developing heart disease. That means even if your LDL and other risk factors are normal, having a low HDL level still increases your risk of heart disease.

What about niacin side effects, like flushing?

Niacin comes in a variety of forms, ranging from fast-acting forms to those that are longer acting. Some forms of niacin, especially in high doses — 1,000 milligrams or more — do cause temporary flushing of the skin.

The flushing can make your skin redden and possibly feel warm to the touch. While annoying, this flushing isn't harmful. If you have flushing, talk to your doctor about taking an aspirin shortly before you take your niacin. Aspirin can counteract this flushing effect. Also, avoiding hot drinks and alcohol can decrease flushing. Versions of niacin with reduced flushing effects also are available by prescription.

Other possible side effects include:

  • Upset stomach
  • Headache
  • Dizziness
  • Liver damage
  • Increased blood sugar

However, your doctor may be able to find the right dose and form of niacin that minimizes side effects. Also, taking niacin with food may help prevent side effects. Remember, don't take niacin — even in the over-the-counter form — without discussing it with your doctor first. Niacin can cause side effects when taken in high doses.

Who might consider taking niacin?

It depends. Niacin has been shown to increase HDL in otherwise healthy people who have normal LDL levels, so your doctor might suggest you take niacin, even if your LDL is relatively normal and you're healthy.

However, don't start taking niacin to raise your HDL without talking to your doctor. Niacin must usually be given at high doses to raise your HDL cholesterol, and the use of high-dose niacin needs to be monitored by your doctor to make sure it doesn't cause any harmful side effects.

Lifestyle changes are also helpful in boosting HDL. These include:

  • Stop smoking if you are a smoker.
  • Eat a healthy diet.
  • Start an exercise program, with your doctor's OK.

If you try steps like this and your HDL is still too low, your doctor may suggest you take niacin.

Niacin is usually given along with statins or other medications to people who have high LDL levels and low HDL. Check with your doctor before taking niacin with another medication to avoid any dangerous drug interactions. However, in general, niacin seems to work even better when used in combination with statins, drugs used to lower your LDL cholesterol. In fact, when used with some statins, niacin can increase your HDL level by 50 percent or more, as well as reduce LDL levels more than when statins alone are used.

Are over-the-counter niacin supplements just as good as prescription niacin when it comes to increasing HDL cholesterol?

Possibly. Supplements sold over-the-counter (OTC) are not regulated like prescription medications. The ingredients, formulations and effect of over-the-counter niacin can vary widely. Again, it's necessary to work with your doctor if you are considering taking niacin to avoid harmful side effects. Don't start taking over-the-counter niacin supplements without talking to your doctor first.