Vitamin B3
Niacin
Last reviewed: June 2026 · Medically reviewed by a licensed pharmacist
What it does
Niacin helps power the chemistry that converts food into energy and keeps your cells' DNA-repair machinery stocked. It's a building block for two molecules (NAD and NADP) that hundreds of reactions in your body depend on every second. Most people get enough from food, but the body's demand for it rises with metabolic stress.
The science
Niacin is a precursor to NAD+, the key coenzyme for energy metabolism, DNA repair, and cellular signalling.
Most relevant for
General energy metabolism. High-dose niacin for cholesterol should only be taken under medical supervision.
Key references
General wellness information, not medical advice. Consult your healthcare provider before starting any supplement. Build your personalized stack →