If there’s one “trendy” skin-care ingredient that comes with benefits that actually deserve your time, it might be hyaluronic acid. Skin-care bloggers and dermatologists alike frequently recommend that nearly everyone incorporate hyaluronic acid into their routines frequently for good reason: It apparently has some intensely hydrating effects.
So what actually is in this magical substance? And what’s the best way to use it? We spoke to a few experts to find out.
What actually is hyaluronic acid?
Hyaluronic acid (HA) is a type of sugar that your body makes naturally: “It’s a sugar, a long-chain carbohydrate present in our body and our skin,” Emily Newsom, M.D., a board-certified dermatologist at Ronald Reagan UCLA Medical Center, tells SELF. It’s also present in lots of nooks and crannies—like between muscle fibers and in the fluid-filled sacs cushioning your joints—but the largest concentration of HA in the body is found in the skin.
It’s the active ingredient in dermal fillers like Restylane, Hylaform, and Juvéderm. And when applied topically, hyaluronic acid acts as a powerful humectant, meaning it draws water to itself. (According to one estimate, a gram of HA can hold up to six liters of water.) “It’s very good at hydrating because it can bind so much water,” Dr. Newsom says.
“When it’s applied topically and it gets absorbed into the skin, it allows additional hydration by attracting water,” Jenny Hu, M.D., associate professor of dermatology (clinician educator), Keck School of Medicine of USC, tells SELF. In doing so, it can both hydrate and plump the skin, making it feel moisturized and softening the look of fine lines, wrinkles, and sagging—often without any added greasiness.
Let’s look at the science on hyaluronic acid.
Hyaluronic acid was first isolated back in the 1930s, so we’ve had decades to study and understand it. We do know a fair amount about how hyaluronic acid works in the body; it’s gone through clinical trials and the FDA approval process in fillers, and it’s used in topical wound treatments. But when it comes to actual clinical trials looking at topical HA for more cosmetic purposes, there’s actually not a whole lot to go on.
What we do have are studies examining the use of hyaluronic acid alongside other ingredients to either help soothe some side effects or more effectively deliver the drug. For instance, in a 2009 study published in the Journal of Cosmetic Dermatology, researchers gave 34 participants taking oral isotretinoin a gel-cream containing hyaluronic acid and 33 participants (also taking isotretinoin) a placebo cream. Oral and topical retinoids are infamous for causing dryness and irritation, but after three months, the group that got the HA gel-cream showed improved hydration, less acne, and less transepidermal water loss than the placebo group. These results suggest that an HA-containing cream can be useful for mitigating the side effects of oral retinoids, medications known to cause dryness.
In another study, this one published in 2014 in the Journal of Cosmetic and Laser Therapy, 23 women applied a serum containing HA and human growth factor (proteins found naturally in the body) twice a day for eight weeks. Compared to their original baseline, participants showed an improvement in signs of aging—specifically, wrinkles around the eyes—after eight weeks. These results are encouraging, but this was a small group and it’s not clear whether the HA or the other ingredients were responsible for any changes.
But the truth is that we’re lacking independent, large-scale clinical trials examining the cosmetic potentials of hyaluronic acid. As one review put it last year, hyaluronic acid cosmetics claim to “restore skin hydration and elasticity, although no rigorous scientific proof is able to fully substantiate this claim.”
That said, Solaraze is a prescription topical medication used to treat actinic keratoses (scaly patches of skin that can be a precursor to skin cancer) containing 3 percent diclofenac in a 2.5 percent hyaluronic acid gel. Research shows that this particular formula is particularly effective without serious side effects. Other research is ongoing to determine whether HA can be used to effectively deliver other topical drugs.
Here’s the best way to use hyaluronic acid in your skin-care routine.
Hyaluronic acid is best used for hydration, so it’s not surprising that it’s already a common ingredient in moisturizers. But it can also be found in facial serums and sprays to add even more hydration in between layers of skin-care products or during the day for a refreshing treat. Note that, in skin-care products, you might also see it listed as sodium hyaluronate (the sodium salt form) or potassium hyaluronate (the potassium salt form).
Dr. Newsom recommends checking out the SkinMedica HA5 Rejuvenating Hydrator, $178, which does have some research backing its famed hydrating powers. She’s also a fan of the cult-favorite Neutrogena Hydro Boost Gel-Cream (specifically the formula for extra-dry skin), $16.
To get even more hydration benefits from hyaluronic acid products, Dr. Hu recommends using them shortly after washing your face or showering, when your face still has a bit of moisture on it. That way you can “trap and retain more of that moisture in your skin,” she explains. However, she adds, any effects you see from using topical hyaluronic acid will be temporary and may even wear off by the end of the day. So if you like the way it makes you look, be prepared to use it every day.
Hyaluronic acid products are great for pretty much every skin type, Dr. Newsom says, but can be beneficial particularly for those with combination skin who are looking for a highly moisturizing product that isn’t too thick or occlusive.
One of the biggest perks of hyaluronic acid is that it’s something that’s already found in your own body, so the chances of feeling irritation from using it are pretty low—even if you have sensitive skin. Of course, it’s always possible to be allergic to or irritated by the other ingredients in any product, but know that hyaluronic acid itself is unlikely to cause a problem. (There are rare instances of allergies, though!)
Not all topical hyaluronic acids are the same: Hyaluronic acid can have a high, medium, or low molecular weight, and research suggests that they do slightly different things. While low and medium molecular weight HAs do the classic hyaluronic acid job of attracting and binding water, higher molecular weight HA tends to have a more occlusive effect, sealing in that hydration. But, in high enough concentrations, some researchers have found that lower molecular weight HA can extract water from the surrounding skin, possibly causing irritation or dryness (basically, the exact opposite of what you’re using hyaluronic acid for).
In practice, though, Dr. Newsom says that molecular weight isn’t really something to spend your time worrying about. And if your hyaluronic acid product is causing irritation it’s far more likely to be due to another ingredient in the product.
Either way, you have a ton of options when it comes to products containing HA. So if you find one that doesn’t work for you, you’ll have plenty of others to choose from. But if you find that you’re consistently getting irritation from your products, it’s worth talking to a board-certified dermatologist to find out what’s causing those issues—and the best way to avoid them in the future.