What is niacin, and how does it work (mechanism of action)?
Niacin (nicotinic acid, vitamin B3) is a part of the normal diet that is essential to various chemical reactions in the body. It is used medically to treat individuals with deficiency of niacin. Advanced deficiency of niacin can lead to a condition called pellagra in which individuals develop diarrhea, dermatitis (inflammation of the skin), and dementia. Niacin also is used to reduce cholesterol and triglyceride levels in the blood. Specifically it reduces bad cholesterol (LDL cholesterol) and increases good cholesterol (HDL cholesterol). It is not clear how niacin causes its effects on cholesterol and triglyceride levels, but it may be by reducing the production of proteins that transport cholesterol and triglycerides in the blood.
Niacin is available in immediate and slow-release forms (Niaspan, Slo-Niacin). Natural sources of niacin include meat, poultry, liver, fish, nuts, green vegetables, whole grains, and potatoes. Niaspan was approved by the FDA in July 1997.
What brand names are available for niacin?
Niacor, Niaspan, Slo-Niacin, Nicolar (discontinued)
Is niacin available as a generic drug?
Do I need a prescription for niacin?
Most formulations are available over the counter.
What are the side effects of niacin?
The most common side effects of niacin are:
- stomach upset,
- reduced blood pressure upon standing (orthostatic hypotension),
- itching and
- tingling sensations of the extremities.
Flushing may be reduced by taking 325 mg of aspirin 30 minutes before the niacin and by increasing the dose of niacin slowly. Drinking hot liquids or alcohol shortly before or after niacin is taken may increase the occurrence of flushing. Extended release formulations of niacin may cause flushing less frequently than immediate release formulations.
Rare cases of liver failure or muscle injury have occurred from the use of niacin. Blood tests to monitor for liver injury should be performed before niacin therapy begins, every 6-12 weeks for the first year, and then occasionally thereafter. Niacin should be discontinued if liver tests are greater than three times the upper limit of normal, are persistently elevated, or are accompanied by nausea, vomiting, or weakness.
What is the dosage for niacin?
The recommended oral dose of immediate release niacin for treating high cholesterol levels in adults is 1-2 g two to three times daily. The maximum recommended dose is 6 g daily. When using extended release tablets, the maximum recommended dose is 2 g per day. Niacin should be started at low doses and increased slowly over several weeks. To avoid stomach upset, niacin should be taken with meals.
Extended release tablets should be swallowed whole and should not be crushed or chewed. Extended release formulations should not be substituted with equivalent doses of immediate release niacin since this leads to an overdose of niacin that may cause liver failure.
Pellagra may be treated with up to 500 mg per day of oral niacin.
Which drugs or supplements interact with niacin?
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Is niacin safe to take if I'm pregnant or breastfeeding?
It is not known whether the high doses of niacin used in treating elevated cholesterol levels are harmful to the fetus during pregnancy.
Niacin is actively secreted in breast milk. Therefore, nursing mothers taking niacin should avoid breastfeeding or discontinue niacin in order to prevent the newborn from ingesting large amounts of niacin.
What else should I know about niacin?
What preparations of niacin are available?
Tablets: 250, 500, 750, and 1000 mg. Capsules: 250 and 500 mg
How should I keep niacin stored?
Niacin should be stored at room temperature from 15 C to 30 C (59 F to 86 F).
Niacin, nicotinic acid, vitamin B3 Niacor, Niaspan, Slo-Niacin, Nicolar (discontinued) is used medically to treat people with niacin deficiency. Advanced deficiency of niacin can lead to pellagra. Niacin is also prescribed for the treatment of high cholesterol and triglyceride levels in the blood. Side effects, drug interactions, warnings and precautions, and patient safety information should be reviewed prior to taking any medication.
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Related Disease Conditions
Liver disease can be cause by a variety of things including infection (hepatitis), diseases, for example, gallstones, high cholesterol or triglycerides, blood flow obstruction to the liver, and toxins (medications and chemicals). Symptoms of liver disease depends upon the cause and may include nausea, vomiting, upper right abdominal pain, and jaundice. Treatment depends upon the cause of the liver disease.
Night sweats are severe hot flashes that occur at night and result in a drenching sweat. The causes of night sweats in most people are not serious, like menopause in women, sleep apnea, medications, alcohol withdrawal, and thyroid problems. However, more serious diseases like cancer and HIV also can cause night sweats. Your doctor will treat your night sweats depending upon the cause. You may experience other signs and symptoms that are associated with night sweats, which depend upon the cause, but may include, shaking, and chills with a fever caused by an infection like the flu or pneumonia; unexplained weight loss due to lymphoma; women in perimenopause or menopause may also have vaginal dryness, mood swings, and hot flashes during the day; and low blood sugar in people with diabetes. Other causes of night sweats include medications like NSAIDs (aspirin, acetaminophen, ibuprofen (Motrin, Advil), and naproxen (Aleve, Naprosyn), antidepressants, sildenafil (Viagra), and abuse of prescription or illegal drugs and drug withdrawal; hormone disorders like pheochromocytoma and carcinoid syndrome; idiopathic hyperhidrosis; infections like endocarditis, AIDs, and abscesses; alcoholism and alcohol withdrawal; drug abuse, addiction, and withdrawal; and stroke. A doctor or other health care professional can treat your night sweats after the cause has been diagnosed.
A stroke is an interruption of the blood supply to part of the brain caused by either a blood clot (ischemic) or bleeding (hemorrhagic). Symptoms of a stroke may include: weakness, numbness, double vision or vision loss, confusion, vertigo, difficulty speaking or understanding speech. A physical exam, imaging tests, neurological exam, and blood tests may be used to diagnose a stroke. Treatment may include administration of clot-busting drugs, supportive care, and in some instances, neurosurgery. The risk of stroke can be reduced by controlling high blood pressure, high cholesterol, diabetes, and stopping smoking.
Eczema refers to skin inflammation. There are many different types of eczema that produce symptoms and signs that range from oozing blisters to crusty plaques of skin. Treatment varies depending upon the type of eczema the person has.
Heart Attack (Myocardial Infarction)
A heart attack happens when a blood clot completely obstructs a coronary artery supplying blood to the heart muscle. A heart attack can cause chest pain, heart failure, and electrical instability of the heart.
Cholesterol (Lowering Your Cholesterol)
High cholesterol and triglyceride levels increase the risk of cardiovascular disease. Getting your cholesterol and triglyceride levels in an optimal range will help protect your heart and blood vessels. Cholesterol management may include lifestyle interventions (diet and exercise) as well as medications to get your total cholesterol, LDL, HDL, and triglycerides in an optimal range.
High Cholesterol: Frequently Asked Questions
Cholesterol occurs naturally in the body. High blood cholesterol levels increase a person's risk of developing heart disease, heart attacks, strokes, TIAs, and more. In addition to medication (fibrates, statins, bile acid sequestrants, and niacin), lifestyle changes can be made to lower blood cholesterol levels
Heart Attack Prevention
Heart disease and heart attacks can be prevented by leading a healthy lifestyle with diet, exercise, and stress management. Symptoms of heart attack in men and women include chest discomfort and pain in the shoulder, neck, jaw, stomach, or back.
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