Niacin is a B vitamin that's made and used by your body to turn food into energy. It helps keep your nervous system, digestive system and skin healthy.

Niacin (vitamin B-3) is often part of a daily multivitamin, but most people get enough niacin from the food they eat. Foods rich in niacin include yeast, milk, meat, tortillas and cereal grains.

People use prescription niacin (Niacor, Niaspan) to help control their cholesterol.

The recommended daily amount of niacin for adult males is 16 milligrams (mg) a day and for adult women who aren't pregnant, 14 mg a day.


Research on the use of oral niacin to treat specific conditions shows:

Niacin deficiency has been linked to birth defects. A study in mice suggested that niacin supplementation during gestation prevented birth defects. Research is needed to prove a similar benefit in humans.

Our take

Generally safe

Prescription niacin might benefit people with high cholesterol who aren't able to take statins or haven't been able to control their cholesterol levels through use of a statin, diet and exercise. Don't take prescription niacin for high cholesterol if you're pregnant.

Side Effects

Niacin Flush and B-Complex Imbalances

One of the most common side effects of high doses of niacin is a "niacin flush." This side effect, while not serious, is characterized by redness, itching and tingling in the neck, face, arms and upper chest. According to the National Institutes of Health, niacin flushing can start at doses of 30 to 50 milligrams and disappearing in 30-45 minutes.

Safety and side effects

When taken orally in appropriate amounts, niacin appears to be safe.

High doses of niacin available via prescription can cause:

Serious side effects are most likely if you take between 2,000 to 6,000 mg of niacin a day. If you think you might have overdosed on niacin, seek medical attention immediately.

If you have liver disease, peptic ulcer disease or severe low blood pressure (hypotension), don't take large amounts of niacin. The supplement has been linked with liver damage, can cause hypotension and might activate a peptic ulcer.

Taking niacin also might worsen allergies, gallbladder disease and symptoms of certain thyroid disorders. If you have diabetes, niacin can interfere with blood glucose control. Use niacin with caution if you have the complex form of arthritis gout. Niacin can cause an excess of uric acid in the blood (hyperuricemia), putting you at risk of gout.

If you're pregnant, don't take prescription niacin for high cholesterol. However, if needed to prevent or treat niacin deficiency, niacin is likely safe to take during pregnancy and in breast-feeding women when used in recommended amounts.


Possible interactions include:


Niacin - Mayo Clinic