Humectants, Explained: How They Work In Skin Care + 8 Natural Options To Try
Layering skin care products is a science, and as you become familiar with what works for your own skin, you might hear a ton of science jargon thrown into those conversations. Such is the case with humectants, emollients, and occlusives: While the monikers may sound incredibly technical, these groups are actually essential for understanding when and how to apply your serums, creams, lotions, et al. Have the chemistry down to a T, and keeping your complexion happily moisturized will be a breeze.
So let's start with the first category, shall we? Below, find everything you need to know about humectants, including how they work, how to use them, and the best options to slather on.
What are humectants?
Humectants pull water into the skin. You might hear "water-loving" or "hydrophilic" tossed around when discussing this ingredient category, and that's because humectants actually bond to water—and this bond allows the ingredients to travel with water as it gets absorbed into the skin cells. On that note: Humectants aren't one ingredient but a class of many water-loving players, like hyaluronic acid, glycerin, and a few other noteworthy hydrators we'll get into later.
How do humectants work?
"Humectants are basically 'water magnets,'" says board-certified dermatologist Ava Shamban, M.D., founder of SKINFIVE. "They work to help pull moisture from the air into the upper layer of your skin to keep the skin cells hydrated, plump with a firmness and bounce." They're able to draw in water from the outside air if the humidity is high enough; and because they bond to water, the humectants can also shimmy into the upper layer of your skin and help keep that water in place.
"Think of the skin as an actual sponge," adds Shamban. "When it is dry, it is thin, brittle, not pliable, rough in texture, dull, and sallow in color. Run it under water, and it is instantly plump, dense, and smooth. Even the color is brighter." The humectants are what help usher that water into the "pores" of the sponge and hold it there, making the appearance plump and full of moisture.
Essentially, humectants are attracted to water—but this can also backfire, specifically in arid environments. See, when the humidity is high, humectants have an easier time pulling in water from the outside air; but when that humidity dips, the humectants can actually pull water from the deeper layers of the dermis into the stratum corneum (or the outermost layer), which can leave your skin drier than before, as water can easily evaporate on the top layer of the skin.
"The magnet forces are attracted to water pulling in or out of the dermis," explains Shamban, so you want to make sure this water magnet is drawing in moisture from the surrounding environment, not from your own skin.
How do you use humectants?
"Humectants should be applied to damp skin, not dry skin (unlike antioxidants, which are best applied on dry skin)," says Shamban. With antioxidant serums—like vitamin C, a famous example—you want those active ingredients to penetrate the skin cells. But because humectants are so water-loving, you actually want to give them the water they need to do their job properly.
Board-certified dermatologist Angelo Landriscina, M.D., seconds the advice: "The humectants in your products, like hyaluronic acid and glycerin, will have an easier time holding on to moisture if you're providing it," he says. Otherwise, those humectants will still do their job—they'll just pull water from your skin instead of the surrounding air, which can leave it even drier than before.
That said, follow these steps:
- After cleansing, simply pat your face with a towel until it's damp before applying your humectant product.
- Or, if your skin feels a little too dry after cleansing (distractions happen!), you can spritz on some facial mist or essence to remoisten your skin. That's why a hydrating toner or essence tends to come before treatment serums anyway, just to make sure those humectants can find the moisture they need.
- After applying, you'll also want to lock in that moisture with an occlusive layer, like a cream or oil (read all about occlusives here). Again, water on the top layer of your skin can easily evaporate, so it's best to slick on an occlusive as the last step of your skin care routine—nothing gets past this water-trapping layer.
Now, many skin care products are actually formulated with a combination of humectants, emollients, and occlusives to reap the benefits of each ingredient category. But if you're putting a raw ingredient on your skin (i.e., a stand-alone hyaluronic acid serum), it's important to mind these application tips above.
What types of products may include humectants?
If a product is marketed as "hydrating" or "moisturizing," there's a pretty good chance it's chock-full of humectants. They're included in a variety of formulas—cleansers, serums, creams, lotions, masks, even shampoos and conditioners—but those leave-on hydrating products (serums, creams, lotions) are where humectants really shine.
8 natural humectants.
Some are famous, others are less-obvious—all are worthy additions to your skin care routine:
We'll start with the most well known: Hyaluronic acid is a fabulous hydrator, as it has the ability to hold 1,000 times its own weight in water1. "It gives an immediate improvement in the way the skin looks—less ashy, dry, dull," holistic dermatologist Cybele Fishman, M.D., told us about the beloved ingredient.
Find our favorite HA serums here.
Take a look at your hydrating products, and chances are you'll see glycerin on the ingredient list. This humectant (typically derived from vegetable oils or animal fats) plays very well with other ingredients, helping round out formulas, and it provides hydration and skin protection. "Along with hydration, glycerin helps with improving the function of the skin barrier, which helps prevent the loss of water, protecting the skin from irritation and improving wound healing in the skin," board-certified dermatologist Raechele Cochran Gathers, M.D., says regarding the ingredient.
Read all about glycerin and our favorite products here.
"The leaf of the aloe vera plant is rich in water, particularly in the innermost layer, so it helps to hydrate the skin and lock in moisture," explains board-certified dermatologist Marisa Garshick, M.D. "The sugars [it contains], also known as mucopolysaccharides, [also] help to retain moisture in the skin." In fact, when applied topically, aloe vera has been shown to increase the water content2 of the stratum corneum.
We can go on and on about the skin-supporting benefits of honey (in fact, we already have!). To summarize: In addition to its humectant properties, honey helps ease inflammation, combat breakouts, and promotes healthy wound healing. It's especially divine as a single-ingredient face mask (just slather on the golden goop for 20 minutes or so), or you can pair it with some of these ingredients to target specific skin concerns.
This oft-overlooked ingredient is actually A+ for soothing the skin: It's structurally similar to vitamin B5 (you might see it listed as provitamin B5 on labels), and according to board-certified dermatologist Jessie Cheung, M.D., panthenol is "a liquid at room temperature, so it's used as a humectant and emollient in skin care products." Animal studies have even found that it increases the mobility of lipids and proteins3 in the stratum corneum, resulting in improved hydration.
You're probably thinking: Uh, isn't lactic acid an exfoliant? It's true: The AHA is best known for gently sloughing off dead skin cells, but it's also considered a humectant.
AHAs in general are hydrophilic, meaning they're water-loving, and in addition to increasing skin cell turnover and reducing the appearance of fine lines, they have also been shown to improve moisture content in the skin4. "They can be simultaneously exfoliating and hydrating, making them very beneficial to many skin types," says board-certified dermatologist Mona Gohara, M.D.
Oats are a known humectant, thanks to their polysaccharides (long sugars) that bind water to the skin's surface. However, the lipids in colloidal oats also have emollient properties (meaning, it has the ability to sit in between skin cells and fill in any micro-cracks, softening irritated skin). With these two moisturizing properties working in tandem, colloidal oats become quite the superfood for skin care. Some people even swear by oatmeal baths to tame irritation and plump the skin with hydration.
This all-natural moisturizer has been used for ages for a very good reason: Cucumbers are immensely hydrating. In fact, the vegetable is 95% water and has anti-inflammatory properties thanks to the antioxidants5 (so say hello to happy, soothed skin). You can DIY a cucumber mask at home by pureeing a cucumber and slathering it on for a few minutes. Just make sure to use a cream or oil afterward to seal in the moisture.
Humectants are water-loving ingredients that plump your skin with hydration—but use them incorrectly, and these water magnets can backfire pretty quickly. No fear: These derm-backed tips and recommendations will have your skin practically bursting with moisture.
Jamie Schneider is the Beauty Editor at mindbodygreen. She has a B.A. in Organizational Studies and English from the University of Michigan, and her work has appeared in Coveteur, The Chill Times, and more. In her role at mbg, she reports on everything from the top beauty industry trends, to the gut-skin connection and the microbiome, to the latest expert makeup hacks. She currently lives in Brooklyn, New York.