Many of you have likely heard about the skin-plumping benefits of hyaluronic acid [1] — one stroll down the beauty aisle and you'll see the popular ingredient [2] listed in moisturizers, serums, facial mists — you name it. The beauty industry is seemingly obsessed with hyaluronic acid [3], as it promises to give us moist and hydrated, baby-smooth skin [4] — sign us up! But what exactly is hyaluronic acid and how does it work? In the kickoff episode of POPSUGAR's latest beauty explainer series, The Makeup [5], host, senior writer, and all-things-beauty expert Kirbie Johnson breaks down how the buzzy ingredient hydrates skin so you can decide if it belongs in your beauty routine. Watch and learn!