LRP La Roche-Posay Effaclar Ultra Concentrate Serum is a concentrated anti-imperfection serum with salicylic acid & niacinamide for oily and acne-prone skin. It is a concentrate of exfoliating acids combined with soothing niacinamide that targets blackheads, pimples, marks and visible pores. This no-rinse formula leaves the skin refined and purified. With a perfect balance between peeling and soothing actions, it unclogs pores and corrects persistent imperfections and marks day after day. It combines a high concentration of synergic actives including 3 keratolytic acids to reduce imperfections and marks, along with niacinamide and thermal spring water for a soothing and anti-redness effect. The tri-acid complex contains salicylic acid 1.5%, glycolic acid 3.5% and LHA 0.45%. Salicylic acid deeply unclogs pores and prevents sebum accumulation, glycolic acid activates skin renewal for improved radiance with high efficacy on marks, and LHA gently micro-exfoliates the skin and refines pores. Niacinamide, also known as vitamin B3, improves the skin barrier, intensely soothes, decreases skin irritation, helps reduce pores and brightens dark spots.