In the skin-care realm, instant gratification is often regarded with suspicion, and rightly so: A formula that promises immediate results can feel disingenuous. Many active ingredients, such as vitamin C, only deliver visible benefits after weeks or months of consistent use. One notable exception is hyaluronic acid (frequently abbreviated as HA), a naturally occurring molecule that’s found within the body. The well-studied ingredient functions as a humectant, meaning it can draw in water and help retain it within the skin, effectively delivering hydration on the spot.
“Think of it as a sponge helping to soak up moisture,” says Marisa Garshick, M.D., a dermatologist in New York City. “This helps to hydrate and keep skin looking and feeling healthy.” While hyaluronic acid is naturally present in the skin at levels necessary to maintain a reasonably smooth, soft complexion, research has found that its production slows over time, leading to crepiness and loss of elasticity.
Replenishing it through topical formulas “can also help to plump the skin, improving the appearance of fine lines and wrinkles,” Garshick says—a good reason that hyaluronic acid often arrives in a serum format, where it can do the lightweight work of permeating the skin. In addition, such products can offset irritation from more potent skin-care treatments, such as chemical exfoliants or retinol creams.
Hyaluronic acid does, however, have a weakness: While it can easily attract water, that water can then evaporate through the skin, through a natural process known as transepidermal water loss. Because of this, says Miami-based dermatologist Heather Woolery-Lloyd, M.D., it’s essential to layer a hyaluronic acid–based formula with a moisturizer that contains emollients or occlusive ingredients, which bolster the skin barrier and thus minimize water loss. Garshick recommends pairing HA serums with ceramides in particular—a key component of the skin’s outer layer—in order to seal hyaluronic acid and its consequent water content in the skin.
Also contributing to hyaluronic acid’s enduring popularity is its efficacy across skin types and concerns. “It’s good for dry skin as long as it’s paired with occlusive moisturizing ingredients,” says Woolery-Lloyd. “And for people with acne-prone skin, hyaluronic acid is noncomedogenic, and most formulations do not leave an oily or greasy residue on the skin.”
However, not all hyaluronic acid is created equal. It comes in an array of molecular weights, or sizes, which allow it to reach corresponding layers of skin. As Garshick puts it: “The different depths may translate to different benefits, with greater molecular-weight hyaluronic acids sitting at the surface to [attract] moisture, and smaller ones penetrating deeper, which draws moisture into a greater depth to provide a plumping benefit.” (Still, Woolery-Lloyd notes, more research is still needed to confirm this theory.)
Whatever the size, though, there’s little to no drawback to be had from incorporating hyaluronic acid into one’s skin-care regimen—and the options below offer perks that make it well worth the addition.