At the high doses of niacin used to treat hyperlipidemia, side effects are common. These include cutaneous flushing (partially prevented by pretreatment with aspirin, 81–325 mg/day, and use of extended-release preparations) and gastric irritation. Elevation of liver enzymes, hyperglycemia, and gout are less common untoward effects.
et al. Assessment of the role of niacin in managing cardiovascular disease outcomes: a systematic review and meta-analysis. JAMA Netw Open. 2019;2:e192224.