Just in time for La Roche-Posay's National Hyaluronic Acid Day on January 21st, start the new year off right with healthier, more luminous skin. Hyaluronic acid - or HA - is a sugar naturally found in our skin that acts like a sponge holding vast amounts of water in the skin, effectively keeping it hydrated, moisturized, and plump. We share our favorite products and regimens with HA and all the latest tips and tricks to get glowing, plumper, and more youthful-looking skin.