Hyaluronic acid is a little like Julia Roberts: a seasoned vet beloved by all, highly dependable, always up for awards, but rarely found at the heart of a viral, buzzy internet moment. The acid has been in just about every moisturizing product around for years, but recently, brands have been trotting out the show pony ingredient and putting it front and center to make us remember just how great it is for every skin type. (Just like how everyone loves Julia.) Need a primer on the superstar hydrator? We've got you.
Despite its scary-sounding name, hyaluronic acid is naturally found in our bodies, which is why our skin — be it oily, dry, mature, or acneic — responds so well when it's introduced artificially. It’s found in almost every skin cell and acts as a cushion that keeps moisture trapped just below the surface. Unfortunately, our stores of the stuff deplete with age, which is why adding it now is the best thing you can do.
One of the best ways to increase hyaluronic acid production? Ingest it. Leafy greens like spinach and kale, starchy root vegetables, and bone broths are good sources of HA. (There are also some freaky sources, like rooster comb and fish eyeballs, if you want to really go above and beyond.)
But what makes hyaluronic acid so good at moisturizing is the fact that it can hold up to 1,000 times its weight in water. Think of it like a soaked sponge that sits under the surface of the epidermis, and steadily drip-feeds skin with moisture throughout the day. As a result, lines look smoother because skin is plumper and dry patches vanish. But because it's a large molecule, it won't penetrate to the deepest layers, so that's where hyaluronic acid fillers, which are made of synthesized HA derived from sodium hyaluronate, come in.