- What is niacin, and how does it work (mechanism of action)?
- What brand names are available for niacin?
- Is niacin available as a generic drug?
- Do I need a prescription for niacin?
- What are the side effects of niacin?
- What is the dosage for niacin?
- Which drugs or supplements interact with niacin?
- Is niacin safe to take if I'm pregnant or breastfeeding?
- What else should I know about niacin?
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?
GENERIC AVAILABLE: Yes
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,
- flushing,
- headache,
- reduced blood pressure upon standing (orthostatic hypotension),
- vomiting,
- diarrhea,
- 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.
Quick GuideLower Your Cholesterol, Save Your Heart
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.








