The best dermatologist-approved hydrating serum you can get only costs $8

Ask any skin expert for advice on combatting dryness, and there’s a 99.9 percent chance that they’ll respond with two words: hyaluronic acid. Because hyaluronic acid is something your body naturally produces, it benefits everyone, regardless of skin type (though, it’s important to note that this production starts declining in our late twenties, much like collagen). But just because it’s an ingredient that’s important for keeping moisture within your skin, it doesn’t have to cost a million dollars.

In our latest episode of Dear Derm, board-certified dermatologist Mona Gohara, MD explains why hyaluronic acid is so beneficial for skin. First of all, it’s a humectant, so it pulls water into your skin and helps keep it there. The all-star ingredient also plumps your skin, so that it looks more like it did when you were a baby (Dr. Gohara points out that when babies are born, they’ve got the most hyaluronic acid they’ll ever have). And, HA can all-in-all create a smooth canvas for all of the steps that follow.

So how do you incorporate it into your routine? Slather it on during the serum step of your routine (or as the last step if you notice that your serum contains silicone, because this ingredient will help seal all the moisture in). As for which one to use, Dr. Gohara recommends many hyaluronic acid serums, from those found at the derm’s office to those you can find for much less money. In fact, one of her go-tos costs less than ten bucks. Watch above to find out which one and to learn more about why hyaluronic acid is a moisturizing must-have. Then, subscribe to Well+Good’s YouTube channel to stay in-the-know on all of the best skin-care secrets, straight from a derm.

For more Dear Derm, here’s intel on how to choose a vitamin C serum that’s right for you. And these are the dry skin ingredients to stock up on (besides hyaluronic acid, of course).