What Is an Emulsion? The 411 on This K-Beauty Staple

If you’re a frequent lurker on TikTok, there’s a solid chance you’ve seen your favorite skincare influencers (skinfluencers?) sing the praises of emulsions. And while watching them pat the product onto their skin, you may have found yourself wondering: What is an emulsion? It’s a valid question—while emulsions are hugely popular in Asian beauty circles, they’re still relatively new for Western beauty enthusiasts. But trust us: these lightweight moisturizers are well worth adding to your routine.

Here, we’ll give you the scoop on what emulsions do, the differences between emulsions vs. moisturizers, and explain how to use an emulsion in your skincare routine. You’ll also get the run down on one of our favorite emulsions for hydrated, healthy-looking skin.

What Is an Emulsion in Skincare?

Emulsions in skincare are best described as lightweight, water-based lotions that contain both oils and, well, water. While oil and water generally don’t readily mix, skincare emulsions also contain emulsifying ingredients that allow the water and oil to blend together homogenously. The resulting formula should be milky or creamy in texture with a distinctly lightweight feel.

Generally speaking, emulsions provide deep, long-lasting hydration without feeling greasy or sticky on the skin. Some formulas may offer additional benefits, too, depending on the ingredients they contain (more on that shortly).

What Are the Benefits of Using Emulsions?

The biggest advantage of emulsions is that they’re hydrating but not heavy. If you have oily skin or live in a warmer climate, you can use a moisturizing emulsion in lieu of a traditional facial moisturizer. And if your skin is on the drier side, you can layer an emulsion under a richer moisturizer for an added boost of hydration—because these formulas are so lightweight and absorb easily, they tend to layer beautifully with other skincare products.

Of course, as we mentioned above, the benefits of a given emulsion will depend on the ingredients it contains—many offer benefits that extend beyond hydration. The Kiehl’s Calendula Skin-Soothing & Stabalizing Emulsion is one such example. This calming formula with a Triple Vitamin B Complex and Calendula flower extract is uniquely designed to help soothe distressed skin. It visibly diminishes redness and blemishes, relieves feelings of discomfort, and helps minimize excess oil. Plus, the lightweight formula helps rebalance the skin’s natural moisture barrier—the integrity of which, as you may know, is essential for healthy-looking skin. The gentle emulsion is suitable for oily, sensitive, and acne-prone skin, and can be used twice daily to help promote a calm, refreshed complexion.

Emulsion vs. Moisturizer

In many ways, emulsions and moisturizers are similar. Both can help hydrate the skin, improve skin texture, and lock in moisture. However, there are a few key differences between emulsions and moisturizers worth pointing out.

Firstly, while moisturizers can be oil-free, emulsions always contain oil—that’s what makes an emulsion an emulsion. Secondly, moisturizers come in many formats, from rich creams to lightweight lotions. Emulsions tend to have a more fluid consistency than your typical moisturizer, thanks to their high water content. And lastly, emulsions can be used alone or in conjunction with a traditional moisturizer. Because they’re so lightweight, applying an emulsion before your moisturizer shouldn’t leave your skin feeling heavy or greasy—just smooth, soft, and deeply hydrated.

If you’re still having trouble spotting the difference between emulsions vs. moisturizers, it may be helpful to think of the former as a hybrid between a hydrating toner and a traditional face lotion.

Emulsion vs. Serum

Emulsions and facial serums differ primarily in what they’re intended to do. Emulsions, as mentioned above, are primarily used for hydrating the skin. Serums, meanwhile, can be used to address an array of skin concerns, from dark spots and discoloration to fine lines or even acne. Serums may also provide hydration, but to a lesser degree than moisturizing emulsions. And while some serums contain oil, it’s not a given. What they do typically contain is a high concentration of so-called active ingredients, such as antioxidants or exfoliating acids.

When you use each in your routine varies, too. When deciding whether to use a serum or emulsion first, you’ll want to remember the golden rule: layer your products in order of consistency from thinnest to thickest. Generally, that means you’d apply your serum (or serums) before your emulsion.

How To Add an Emulsion to Your Skincare Routine

If you’re wondering “What step is an emulsion in skincare?” you’ll want to consider the other products you use. As we mentioned above, it’s generally best to apply your products in order of consistency from thinnest to thickest—and where exactly emulsion falls on that spectrum depends on what else is in your lineup/

That said, you’ll always want to start your routine by cleansing your skin to remove dirt, oil, and other debris. Then, you can apply a toner—if you use one—and layer on a serum designed for your skin type and concerns. (You can see some of our favorites here).

After that would come your emulsion. If you have oily skin or live in a humid environment, you could jump straight to sunscreen after your emulsions aborbs. Otherwise, pat the emulsion onto your skin, allow it a moment to absorb, then apply your moisturizer. During the daytime, you’ll also want to finish off your routine with a broad-spectrum sunscreen to help protect your skin from damaging UV rays (even if it’s cloudy out).

Your nighttime routine would follow the same general steps, only without the sunscreen. If you need extra hydration, consider rounding off your routine with a lightweight facial oil to help lock in all that moisture.

Next Up: How Occlusive Ingredients Can Benefit Dry Skin