Why Choose Our Niacinamide 500mg Tablets?. ✔️ High-Strength Formula – 500mg of pure Niacinamide per tablet. Niacin (Vitamin B3 as Niacinamide), Bulking agents; Microcrystalline Cellulose, Dicalcium Phosphate; Hydroxypropyl Cellulose, Anti-caking Agents (Silicon Dioxide, Stearic Acid & Magnesium Stearate).