Along with its needing effects, a dietary supplement may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your health care professional immediately if any of the following side effects was happen
With injection only
Skin rash or itching; wheezing
With prolonged use of extended-release niacin
Darkening of urine; light gray-colored stools; loss of appetite; severe stomach pain; yellow eyes or skin
Other side effects may occur that usually don't needed medical attention. These side effects may go away during treat as your body adjusts to the dietary supplement. However, check with your health care professional if any of the following side effects continue or are bothersome:
Less common with niacin only
Feeling of warmth; flushing or redness of skin, especially on face and neck; headache
With high doses
Diarrhea; dizziness or faintness; dryness of skin; fever; frequent urination; itching of skin; joint pain; muscle aching or cramping; nausea or vomiting; side, lower back, or stomach pain; swelling of feet or lower legs; unusual thirst; unusual tiredness or weakness; unusually fast, slow, or irregular heartbeat
More common side effects not listed above may also occur in some individuals. If you have any other problems, check with your health care professional.