Niacin Capsules and Tablets

Niacin is a vitamin that (in large doses) can help you improve your cholesterol numbers. This can help lower your risk of cardiovascular disease. People with certain medical conditions shouldn’t take niacin. Also, other medicines may interact with niacin. Your healthcare provider can tell you if niacin is a good fit for you.


What is this medication?

NIACIN (NYE a sin) prevents and treats low niacin levels in your body. Niacin (vitamin B3) plays an important role in maintaining the health of your heart, blood vessels, and metabolism. It may also be used with other medications to decrease bad cholesterol and fats (such as LDL, triglycerides) and increase good cholesterol (HDL) in your blood.

This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.



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What should I tell my care team before I take this medication?

They need to know if you have any of these conditions:

  • Bleeding problems
  • Frequently drink alcohol
  • Liver disease
  • Ulcers of intestine or stomach
  • An unusual or allergic reaction to niacin, other medications, foods, dyes, or preservatives
  • Pregnant or trying or get pregnant
  • Breast-feeding

How should I use this medication?

Take this medication by mouth with water. Take it as directed on the label at the same time every day. Take it with a low-fat meal or snack. Keep taking it unless your care team tells you to stop.

Talk to your care team about the use of this medication in children. Special care may be needed.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

NOTE: This medicine is only for you. Do not share this medicine with others.


What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

What may interact with this medication?

  • Aspirin
  • Medications for blood pressure, chest pain, or heart disease
  • Medications for cholesterol or triglycerides
  • Nitroglycerin
  • Nutritional supplements that contain niacin or nicotinamide

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.


What should I watch for while using this medication?

Visit your care team for regular checks on your progress. Tell your care team if your symptoms do not start to get better or if they get worse. You may need blood work while you are taking this medication.

This medication may affect your coordination, reaction time, or judgment. Do not drive or operate machinery until you know how this medication affects you. Sit up or stand slowly to reduce the risk of dizzy or fainting spells. Drinking alcohol with this medication can increase the risk of these side effects.

Do not drink hot drinks or alcohol at the same time you take this medication. Hot drinks and alcohol can increase the flushing caused by this medication, which can be uncomfortable. Alcohol also can increase possible dizziness. Taking aspirin or an NSAID, such as ibuprofen, 30 minutes before this medication may help reduce flushing.

Taking this medication is only part of a total heart healthy program. Ask your care team if there are other changes you can make to improve your overall health.

If you are a person with diabetes, close regulation and monitoring of your blood sugars can help your blood fat levels. This medication may change the way your diabetic medication works, and will sometimes require that your dosages be adjusted. Check with your care team.

What side effects may I notice from receiving this medication?

Side effects that you should report to your care team as soon as possible:

  • Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
  • High blood sugar (hyperglycemia)—increased thirst or amount of urine, unusual weakness or fatigue, blurry vision
  • Liver injury—right upper belly pain, loss of appetite, nausea, light-colored stool, dark yellow or brown urine, yellowing skin or eyes, unusual weakness or fatigue

Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):

  • Bloating
  • Burping
  • Facial flushing, redness
  • Gas

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Where should I keep my medication?

Keep out of the reach of children and pets.

Store between 15 and 30 degrees C (59 and 86 degrees F). Keep the container tightly closed. Get rid of any unused medication after the expiration date.

To get rid of medications that are no longer needed or have expired:

  • Take the medication to a medication take-back program. Check with your pharmacy or law enforcement to find a location.
  • If you cannot return the medication, check the label or package insert to see if the medication should be thrown out in the garbage or flushed down the toilet. If you are not sure, ask your care team. If it is safe to put it in the trash, empty the medication out of the container. Mix the medication with cat litter, dirt, coffee grounds, or other unwanted substance. Seal the mixture in a bag or container. Put it in the trash.

NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.

Additional Common Questions

What does niacin do?

A prescription form of niacin (over 100 times the recommended dietary allowance) treats high cholesterol. It can increase HDL or “good” cholesterol by up to 30% and decrease LDL or “bad” cholesterol by up to 25%. Also, it can lower your triglyceride levels by up to 50%.

What does niacin do for the body?

Niacin plays a role in taking energy from what you eat and putting it into a form of energy your body can use. It also helps your cells with certain functions, like communicating with each other.

Is it OK to take niacin daily?

Yes, some people can take niacin daily. But niacin isn’t for everyone. Certain medical conditions (like liver disease and peptic ulcers) prevent people from taking niacin. Also, some medications interact with niacin. A healthcare provider may want to give you blood tests every six months while taking niacin. They’ll check your liver function and blood sugar to make sure the drug isn’t causing harm.

A note from Cleveland Clinic

It’s frustrating to see high cholesterol numbers in your test results, especially if you’ve worked to make changes to what you eat and how often you exercise. Many people are in the same situation and need to take medication to improve their cholesterol numbers. Niacin may be a good option for some people and not others. Ask your healthcare provider if niacin is right for you.

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Note: Introduction and Additional Common Questions written and medically approved by Cleveland Clinic professionals.

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