What You Should Know About Niacin Supplements

A Guide to Choosing the Right One

In This Article

Niacin is a form of vitamin B, specifically B3 (nicotinic acid). It's a water-soluble vitamin important for proper cell function in the body. Niacin has been studied for its potential to treat an array of diseases and conditions, including Alzheimer's disease, cataracts, erectile dysfunction, and sickle cell disease, with little success. At one time doctors niacin supplementation to help manage cholesterol levels in people with cardiovascular disease. However, in light of research that found niacin not only did not work for this purpose but also increased the risk of stroke, the practice is no longer recommended.

Most people get enough niacin in their diets to prevent a deficiency. It's readily available in a number of common foods, including yeast, meat, fish, milk, eggs, green vegetables, and fortified cereal. However, if your doctor or a nutritionist has determined you should be getting more vitamin B3 in your diet, there are things to consider when you choose and use niacin supplements.

Immediate-Release Nicotinic Acid

Immediate-release (IR) nicotinic acid, also known as "fast-release" nicotinic acid, goes into your blood as soon as you take it. Because the whole dose goes into your blood at the same time, IR nicotinic acid is also the form that causes the majority of niacin-induced side effects such as flushing, warmth, and itching.

Some bottles of nicotinic acid may not state if they contain an “immediate-release” or a “sustained-release” (see below) product. If the label doesn't say which form of nicotinic acid is in the bottle, it's safe to assume that it's an IR product.

Sustained-Release Nicotinic Acid

Sustained-release (SR) nicotinic acid, also known as "timed-release" nicotinic acid, is designed to release nicotinic acid into your body over a period of time instead of all at once. If you take an SR nicotinic acid product, you may experience niacin-induced side effects, but they usually won't be as uncomfortable as you'd feel if you were taking an IR product.

You need to know that the SR form of nicotinic acid takes the longest of the three forms to leave your body completely. That means that it stays in your body longer than the IR or ER form. For this reason, people taking SR nicotinic acid have an increased risk of liver toxicity, which is rare in those taking IR and ER products. To reduce your risk of liver toxicity, you may want to take an ER form of nicotinic acid instead of an SR form.

Extended-Release Nicotinic Acid

This type of nicotinic acid can be obtained with a prescription from your doctor under the trade name Niaspan. (Slo-Niacin, an OTC controlled-release product, may be less expensive.)

Extended-release (ER) nicotinic acid fits somewhere in between the IR and SR forms of nicotinic acid. Its release into your body is a little slower than with the IR form, but it's faster than with the SR form. Side effects still may occur, but again, they're not as severe as with the IR form. Additionally, there are no problems with liver toxicity associated with this form of nicotinic acid.

Possible Side Effects

While niacin supplements may be safe for many people, there are some side effects to be aware of. Some people experience flushing when they take it and the supplement may cause burning, tingling, itching, and redness of the face, arms, and chest, as well as headaches. Consuming alcohol may make your symptoms worse.

Less common side effects of niacin include stomach upset, intestinal gas, dizziness, and pain in the mouth.

Higher doses (over three grams per day) may cause more severe side effects including liver problems, gout, ulcers of the digestive tract, loss of vision, high blood sugar, irregular heartbeat, and other serious problems. There are also concerns about an increased risk of stroke in people taking niacin.
For these reasons, it is important that you work with your healthcare provider if you choose to take niacin supplements.

Dosage and Preparation

There is not enough scientific data to provide a single recommended dose of niacin or nicotinic acid. The appropriate dose for you may depend on factors including your age, gender, and medical history.

Speak to your healthcare provider to get personalized advice. Your provider can work together with you to come up with a plan to manage your medical condition and stay healthy.

What to Look For

Even if you're buying nicotinic acid over the counter rather than with a prescription, don't think of it as "only a supplement." it's still a form of medication, despite the fact that another name for it is "vitamin B3." Be sure to get your doctor's okay before you start taking it, and report any severe side effects to your doctor right away.

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Article Sources

  • Niacin. Natural Medicines Database. Professional Monograph. 2/6/2019

  • Niacin. Fact Sheet for Health Professionals. National Institutes of Health Office of Dietary Supplements.

  • Nicotinamide. Memorial Sloan Kettering Cancer Center. About Herbs, Botanicals, and Other Products. July 18, 2017

  • Boden We, Probstfield JL, Anderson T, et al. Niacin in Patients With Low HDL Cholesterol Levels Receiving Intensive Statin Therapy. N Engl J Med. 2011 Dec 15;365(24):2255-67. doi:10.1056/NEJMoa1107579


  • Pieper JA. "Understanding niacin formulations." Am J Manag Care. 2002; 8(12):S308-S3014.
  • “Niacin and cholesterol.” University of California, Berkeley-Berkeley Wellness (2011).