Niacin, also called nicotinic acid, is a B vitamin (vitamin B3). It occurs naturally in plants and animals, and is also added to many foods as a vitamin supplement. It is also present in many multiple vitamins and nutritional supplements.
Niacin is used to lower blood levels of "bad" cholesterol (low-density lipoprotein, or LDL) and triglycerides, and increase levels of "good" cholesterol (high-density lipoprotein, or HDL).
Niacin may also be used for purposes not listed in this medication guide.
You should not take niacin if you have severe liver disease, a stomach ulcer, or active bleeding.
Niacin can cause certain side effects, such as flushing (warmth, itching, redness, or tingly feeling under your skin). These effects can be made worse if you drink alcohol or hot beverages shortly after you take this medicine. These effects should disappear over time as you keep taking the medication.
Avoid getting up too fast from a sitting or lying position, or you may feel dizzy. Get up slowly and steady yourself to prevent a fall.
Avoid taking colestipol (Colestid) or cholestyramine (Locholest, Prevalite, Questran) at the same time you take niacin. If you take either of these other medications, take them at least 4 to 6 hours before or after you take this medicine.
Niacin is only part of a complete program of treatment that may also include diet, exercise, weight control, and other medications. Follow your diet, medication, and exercise routines very closely.
You should not take niacin if you are allergic to it.
To make sure you can safely take niacin, tell your doctor if you have ever had:
severe liver disease;
a stomach ulcer; or
Tell your doctor if you have ever had:
heart disease, chest pain (angina);
It is not known whether niacin will harm an unborn baby. You may not be able to use this medicine during pregnancy. Tell your doctor right away if you become pregnant.
You should not breastfeed while using this medicine.
Niacin is not approved for use by anyone younger than 18 years old.
Use niacin exactly as directed on the label, or as prescribed by your doctor. Read all medication guides or instruction sheets.
Niacin can cause flushing (warmth, itching, redness, or tingly feeling under your skin). These effects should disappear over time as you keep taking the medicine. Flushing may be worse if you drink alcohol or hot beverages shortly after taking niacin.
Swallow the capsule or tablet whole and do not crush, chew, break, or open it.
Your dose needs may change if you switch to a different brand, strength, or form of this medicine. Avoid medication errors by using only the form and strength your doctor prescribes.
If you stop taking niacin for any length of time, talk with your doctor before starting the medication again. You may need to restart the medication at a lower dose.
This medicine can affect the results of certain medical tests. Tell any doctor who treats you that you are using this medicine.
Niacin is only part of a complete treatment program that may also include diet, exercise, and weight control. Follow your diet, medication, and exercise routines very closely.
Your doctor may recommend you take aspirin or an NSAID (such as ibuprofen, Advil, or Aleve) to help prevent flushing. Keep using these medicines for as long as your doctor has prescribed.
Store at room temperature away from moisture and heat.
Detailed Niacin dosage information
Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
Avoid drinking alcohol. It may increase your risk of liver damage, and can also worsen the flushing effects of niacin.
Avoid getting up too fast from a sitting or lying position, or you may feel dizzy.
Avoid eating foods high in fat or cholesterol, or niacin will not be as effective.
Get emergency medical help if you have signs of an allergic reaction to niacin: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have:
a light-headed feeling, like you might pass out;
severe warmth or redness under your skin;
vision problems; or
jaundice (yellowing of the skin or eyes).
Common niacin side effects may include:
flushing (sudden warmth, redness, or tingly feeling);
upset stomach, vomiting, diarrhea;
abnormal liver function tests;
itching, dry skin;
skin discoloration; or
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Niacin side effects (more detail)
Tell your doctor about all your other medicines, especially:
statin cholesterol medication;
heart or blood pressure medication; or
other medicines that lower blood pressure.
This list is not complete. Other drugs may interact with niacin, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.