Niacin Therapy: Potential Adverse Effects

Niacin or vitamin B3 is a water-soluble B-complex vitamin that helps the digestive system metabolize food and produce energy. It's also necessary for proper function of the nervous system and contributes to skin health. Sometimes, doctors prescribe or recommend niacin to help manage cholesterol levels and reduce the risk of cardiovascular disease. Although niacin is an essential vitamin, supplements may cause unwanted side effects.

1. Niacin Flush

Niacin flush may be the most well-known side effect of niacin supplements. It causes the skin, especially on the face and neck, to redden and feel warm. Some people also feel burning, tingling, or itching. Flushing occurs because small capillaries in the skin become dilated, and this increases blood flow near the surface.

A niacin flush usually occurs 10 to 20 minutes after consuming a large dose of the vitamin — approximately 100 milligrams or more. The sign will slowly fade away within 30 minutes to two hours. Although flushing can be uncomfortable, it's usually not harmful.