L'Oréal Paris Hair Expertise Glycolic Gloss Sulfate-Free Shine Shampoo. This shampoo is powered by a 2% Glycolic Acid Gloss Complex that penetrates deeply into the hair fiber to improve hair quality and seal cuticles with a lasting glossy effect. Perfect for dull, porous hair, this shampoo transforms your hair, leaving it 2x shinier and 88% smoother for up to 10 washes.