Safety Profile
Overall safety rating: Safe with Caution
Vitamin B3 (Niacin) Side Effects & Safety
This content is for informational purposes only and does not constitute medical advice. Consult your healthcare provider before starting any supplement. Full disclaimer
Potential Side Effects
- Niacin flush — redness, warmth, and tingling of skin (prostaglandin-mediated); dose-dependent
- Hepatotoxicity with sustained-release niacin at high doses
- GI discomfort including nausea, vomiting, and diarrhea at high doses
- May worsen gout by increasing uric acid levels
- Niacinamide and NR generally well-tolerated without flushing
Drug & Supplement Interactions
- Statins — combined use with high-dose niacin may increase myopathy risk
- Alcohol increases flushing and hepatotoxicity risk with niacin
- Aspirin (325 mg, taken 30 min before) reduces niacin flush
- Blood pressure medications — niacin may enhance hypotensive effects
- Anticoagulants — niacin may enhance effects
Maximum Dose
Do not exceed: 35 mg/day NE from supplements (UL to avoid flushing); therapeutic niacin up to 3,000 mg under medical supervision
References
- AIM-HIGH Investigators, Boden WE, Probstfield JL, et al. (2011). Niacin in patients with low HDL cholesterol levels receiving intensive statin therapy. New England Journal of Medicine. DOI PubMed
- Chen AC, Martin AJ, Choy B, et al. (2015). A phase 3 randomized trial of nicotinamide for skin-cancer chemoprevention. New England Journal of Medicine. DOI PubMed
- Martens CR, Denman BA, Mazzo MR, et al. (2018). Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults. Nature Communications. DOI PubMed