paula's choice clinical 20% niacinamide vitamin b3 concentrated serum, anti-aging treatment for discoloration and minimizing large pores, fragrance-free & paraben-free, 0.67 ounce dropper bottle paula's choice this innovative serum is the first ever to contain niacinamide at a safe, effective 20% concentration. this advanced level, complemented by purslane and acetyl glucosamine, steadily smooths out rough, orange-peel texture and tenacious bumps. niacinamide (vitamin b3) is a smart, multifaceted ingredient that uniquely penetrates skin’s surface to help improve the look of sagging, stretched pores. it normalizes pore function and protects from further stretching when exposed to damaging uv light for a dramatically smoother, younger-looking complexion. apply a few drops of niacinamide 20% once or twice daily after cleansing, toning, and exfoliating. at night, layer with other treatment products as needed and follow with moisturizer; during the day, finish with a sunscreen rated spf 30 or greater.