What side effects may I notice from receiving Niacin (Vitamin B3)?

Side effects that you should report to your doctor or health care professional as soon as possible:
-allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
-dark urine
-feeling faint or lightheaded, falls
-general ill feeling or flu-like symptoms
-light-colored stools
-loss of appetite, nausea
-palpitations
-right upper belly pain
-shortness of breath, wheezing
-skin rash and itching
-unusually weak or tired
-yellowing of the eyes or skin

Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):
-diarrhea
-headache
-stomach discomfort or bloating

This list may not describe all possible side effects for Niacin (Vitamin B3). Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.