Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

B-3 Niacin

Side Effects

List B-3 Niacin side effects by likelihood and severity.

The following side effects are associated with B-3 Niacin:

Common side effects of B-3 Niacin:

  • CoughLess Severe
  • DiarrheaLess Severe
  • Feel Like Throwing UpLess Severe
  • IndigestionLess Severe
  • ItchingLess Severe
  • Temporary Redness of Face and NeckLess Severe
  • Throwing UpLess Severe

Infrequent side effects of B-3 Niacin:

  • Abnormal Heart RhythmLess Severe
  • Decreased Blood PlateletsLess Severe
  • DizzyLess Severe
  • Dry EyeLess Severe
  • Dry SkinLess Severe
  • Feeling FaintLess Severe
  • Head PainLess Severe
  • High Amount of Uric Acid in the BloodLess Severe
  • High Blood SugarLess Severe
  • Low Amount of Phosphate in the BloodLess Severe
  • Muscle PainLess Severe
  • Stomach CrampsLess Severe
  • Worsening of Peptic UlcerLess Severe

Rare side effects of B-3 Niacin:

  • A Spasm of the LarynxSevere
  • Abnormal Liver Function TestsSevere
  • Giant HivesSevere
  • Hepatitis caused by DrugsSevere
  • HivesSevere
  • Life Threatening Allergic ReactionSevere
  • Macular EdemaSevere
  • Muscle ProblemsSevere
  • Numbness and TinglingSevere
  • Trouble BreathingSevere
  • Visible Water RetentionSevere
  • Yellowing of Skin or Eyes from Liver ProblemsSevere
  • Abnormally Low Blood PressureLess Severe
  • Blood Pressure Drop Upon StandingLess Severe
  • Blurred VisionLess Severe
  • BurpingLess Severe
  • ChillsLess Severe
  • Chronic Trouble SleepingLess Severe
  • Decrease in the Blood-Clotting Protein ProthrombinLess Severe
  • Excessive SweatingLess Severe
  • Feeling WeakLess Severe
  • GasLess Severe
  • Heart Throbbing or PoundingLess Severe
  • Migraine HeadacheLess Severe
  • Muscle WeaknessLess Severe
  • NervousLess Severe
  • RashLess Severe
  • Skin DiscolorationLess Severe

Selected from data included with permission and copyrighted by First Databank, Inc. This copyrighted material has been downloaded from a licensed data provider and is not for distribution, expect as may be authorized by the applicable terms of use.

CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.

More about Drugs and Medications


Subscribe to free WebMD newsletters.

  • WebMD Daily

    WebMD Daily

    Subscribe to the WebMD Daily, and you'll get today's top health news and trending topics, and the latest and best information from WebMD.

  • Men's Health

    Men's Health

    Subscribe to the Men's Health newsletter for the latest on disease prevention, fitness, sex, nutrition, and more from WebMD.

  • Women's Health

    Women's Health

    Subscribe to the Women's Health newsletter for the latest on disease prevention, fitness, sex, diet, anti-aging, and more from WebMD.

By clicking Submit, I agree to the WebMD Terms & Conditions & Privacy Policy and understand that I may opt out of WebMD subscriptions at any time.

URAC: Accredited Health Web Site TRUSTe online privacy certification HONcode Seal AdChoices