If there’s one skin-care ingredient that puts you in the fast lane to hydrated skin, hyaluronic acid is it. You’ll find it as an active ingredient in seemingly every skin-care product category under the sun — serums, cleansers, moisturizers, and more. There’s a reason it’s ubiquitous: Not only does hyaluronic acid do a killer job when it comes to moisturizing the skin, but it has an anti-aging effect because plump, hydrated skin makes fine lines and wrinkles less visible.

Here’s everything you need to know about hyaluronic acid.