Everything You Need to Know About Hyaluronic Acid

Let's talk about the state of your skin. Is it itchy? Dehydrated? Does it feel a little tight? Hyaluronic acid can help with all that and more. You've probably heard of the ingredient beforeit's in everything from serums to sheet masks to even lip filler. But if you're new to H.A. (as skin care experts often refer to it), you're about to see a lot more of it in the coming months, because it's the active ingredient in nearly every major skin-care launch.

Here's the scoop on the moisturizing powerhouse that all derms swear byand the stuff you'll soon be telling everyone you know about.

What is hyaluronic acid?

Acid may be the last thing you want to put on your parched face, but hyaluronic acid isn't the kind that burns (like alpha or beta hydroxy acids, which work to exfoliate your skin). H.A. is a substance that occurs naturally in your bodyin your joints, eyes, andyesskin.

So what purpose does it serve in the latter? It's produced by fibroblasts, the same cells that make collagen, in the dermis, the second layer of skin, says Neal Schultz, M.D., NYC dermatologist and founder of BeautyRx by Dr. Schultz. It's the key molecule involved in skin moisture because it absorbs up to 1,000 times its weight in water. Think of hyaluronic acid as a sponge in your skin that holds on to moisture and keeps your face looking plump and dewy.

What are the benefits of hyaluronic acid?

Hyaluronic acid does not occur naturally on the surface of your skin, but when applied [via skin care], it's a wonderful moisturizing ingredient, says Schultz. When you apply an H.A. product, it works as a humectant. Humectants basically pull water from the environment into your skin and are very hydrating, says Joanna Vargas, celebrity facialist and founder of Joanna Vargas Skincare Collection. Basically, it serves as a big drink of water for your face, softening fine lines, making skin look firmer, and smoothing out even the roughest dry patches.

It also plumps and adds volume to your skin cells to make your skin more radiant and smooth, says Jessica Weiser, M.D., a dermatologist at New York Dermatology Group. H.A. is also a popular ingredient for facial fillers. We use hyaluronic acid fillers to replace volume, create lift, and make the contours of the face more youthful, says Weiser.

How do use hyaluronic acid?

Humectants like hyaluronic acid typically have a watery texture and absorb quickly (think liquidy serums), whereas emollients (i.e., creams and oils) are thicker and stay more on your skin's surface, don't absorb as quickly, and work to lock everything in. Hyaluronic acid is often combined with other runny humectants (like glycerin and urea) and water. The water part is important: It gets bound by the hyaluronic acid and then delivered to your skin', says Schultz. 'This is one of the ways hyaluronic functions as the greatest moisturizing ingredient ever.

But here's the thing to remember with humectants: It's important to combine or layer them with more emollient textures, as the thicker products will work to maintain the moisture the humectant provides. They seal in moisture that is already there so it doesn't evaporate, says Schultz. A good rule of thumb: You'll want to top off an H.A. serum with an oil or a cream to make the results last. Most creams, on the other hand, already have both humectants and emollients (we like BeautyRX Soothing Moisture Cream), so they're okay to apply alone. (Or, if your skin is super oily, a serum may be enough.) I personally always use bothserums because they have more powerful levels of active ingredients, and then a cream as a veil of protection. Vargas also points out that regular exfoliation is key for getting the most out of your products. Hyaluronic acid absorbs so much better if you don't have a layer of dead skin cells sitting on the surface.

What are the best hyaluronic acid serums?

Good Q. Here are all the top-recommended products that deliver H.A., and which will work best for your skin type or concern.

1. If you have extremely dry skin

Clarins Hydra-Essentiel Intensive Moisture Quenching Bi-Phase Serum

This Clarins serum has two different textures, and when you shake and apply the mixture to your face, it'll revive even the most dehydrated skin. The active ingredient, along with H.A.: a succulent called the Leaf of Life, which is native to Madagascar and able to thrive amid harsh weather changes.

2. If you want to treat fine lines

Kate Somerville Wrinkle Warrior 2-in-1 Plumping Moisturizer and Serum

Kate Somerville's moisturizer-serum hybrid is thick enough that you can probably get away with skipping your cream altogether. It packs three different sizes of hyaluronic acidlarge, medium, and minito penetrate skin at various levels. It also has a few different amino acids that work to lessen lines and winkles. Bonus: Whereas some hyaluronic products can leave skin a bit tacky, this gel leaves your face completely soft and matte, minimizing lines and doubling as a makeup primer.

3. If your skin is looking a little tired

SkinCeuticals Hyaluronic Acid Intensifier

Anytime Skinceuticals releases a serum, it's a big deal. The brand's H.A. Intensifier not only contains 1.3% H.A. in various formats (fragmented, encapsulated, and at full molecular weight) to soften your skin, but also has purple rice extract (why it has a violet hue) and Pro-Xylane, to stimulate your skin's cells that make collagen, boost H.A. levels, and prevent its natural breakdown. The takeaway: Most H.A. products work to hydrate the surface of your skinthis does that and helps build up the reservoir of H.A. in your dermis. Major.

4. If you prefer clean products

Drunk Elephant B-Hydra Intensive Hydration Gel

Drunk Elephant's B-Hydra Intensive Hydration Gel doesn't contain hyaluronic acid per se, but it does have sodium hyaluronate crossploymer, a relative ingredient that the brand calls H.A.'s adorable little sister. According to Schultz, sodium hyaluronate is functionally the same thing as our beloved hyaluronic acid, so this will also work to rehydrate parched skin. One benefit of it is that it has a smaller molecule size than naturally occurring H.A., so it can penetrate deeper into your skin.

5. If you prefer a cream texture

Glamglow Thirstymud Hydrating Treatment Mask

There's a reason Glamglow's Thirstymud Hydrating Mask is so popular. It feels dreamy when you apply it to your face at the end of a long day. It's also extremely lightweight and leaves skin with an instant silky, soft, and supple feel.

6. If you have oily skin

L'Oral Revitalift Derm Intensives Hyaluronic Acid Serum

Try L'Oral's Revitalift H.A. serum. The beautiful thing about hyaluronic acid and most humectantsis that they won't clog pores. Because oily skin needs moisture too (and can get even greasier if you attempt to dry it out), L'Oral's aloe vera and H.A.-laced serum delivers moisture and a matte finish for those who battle shine.

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