Human: What are the side effects of taking niacin? Assistant: 
The most common side effects of taking niacin include nausea, flushing, stomach pain, headache, and dizziness. Less common side effects may include skin rash, itching, and difficulty breathing. Rarely, more serious side effects such as liver damage or anaphylaxis can occur. If you experience any of these symptoms while taking niacin, contact your doctor immediately.