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  • Moisturizer: The Definition and Some Distinctions
  • Post author
    Kay Beauty

Moisturizer: The Definition and Some Distinctions

Moisturizer: The Definition and Some Distinctions

Hello again, beauties!

It’s me, Kay Beauty, and today I’m here to tell you what you need to know about different moisturizing ingredients to get you that perfectly plump, smooth, and silky skin you’ve been dreaming of!

Moisturizer: The Definition and Some Distinctions

So what is “moisturizer”? At first, the answer seems obvious. Moisturizer is a product that adds moisture to skin. For those of us in the West, the word “moisturizer” usually brings to mind lotions or creams. But there’s actually a lot more to moisturizer than that, especially if your goal is juicy, bouncy K-beauty skin.

To understand different types of moisture, first we need to consider the structure of our skin and its different moisture needs.

The primary function of skin is to keep things inside that should be inside, and to keep things out that should stay out. That includes moisture. At the upper layers of skin, this is accomplished through what we know as our “moisture barrier.” Our moisture barrier is comprised of dead skin cells and fatty lipids arranged in a kind of brick and mortar structure. This structure helps to hold water in our skin and keep irritants and contaminants out. Deeper within our skin, water is key. Water maintains our cells’ shape and proper function. Water in the deeper levels of skin keep our complexions plump and give it a dewy glow.

To stay in top condition, therefore, our skin needs both watery and fatty moisture. Unfortunately, we can lack either or both of those types of moisture for many reasons. Overly harsh cleansing and/or too much exfoliation can compromise our moisture barrier and lead to rapid water loss, dehydrating skin. Dry skin, on the other hand, is caused by too little production of lipids in skin. And the aging process reduces our natural production of both.

Here's where moisturizers come in. To choose the right ones for your skin, understand the different types of moisturizing ingredients they use, and arrange your skincare routine accordingly. Most products contain a mix of more than one type of moisturizing ingredient, but in different proportions for different results.


Humectants are ingredients that bind water and deliver it to skin. They are used to hydrate skin and are best for plumping and to smooth away fine lines and crepey texture caused by dehydration. Some of the most common humectants are glycerin and hyaluronic acid/sodium hyaluronate/hydrolyzed hyaluronic acid. You’ll find humectants most strongly represented in hydrating toners and watery-type sheet masks. Use these to deliver water deep into skin.

My picks for humectant moisture:


Emollients are ingredients that fill in the microscopic gaps between cells at the surface of the skin. Remember the brick and mortar structure we talked about earlier? If there are any cracks, crevices, or other holes in that structure, emollients temporarily seal those up. This creates a soft texture and smooth, supple surface. Plant oils are very common emollients in Korean skincare. Snail secretion filtrate or snail mucin is also wonderfully emollient. Emollients are most strongly represented in moisturizing lotions and creams, as well as in creamy-type sheet masks.

My picks for emollient moisture:


Occlusives are moisturizing ingredients that sit on top of skin, due to having molecules too large to penetrate into skin. Usually heavier than emollients, they create a physical barrier to prevent moisture loss. The most common occlusives in skincare are mineral oil and petroleum jelly, but when used in large enough proportions, emollients such as ceramides and plant oils also become occlusive. Shea butter is another common occlusive. Occlusives are most often emphasized in heavier moisturizing creams and sleeping packs.

My picks for occlusive moisture:


Most effective skincare routines will contain a mix of all three types of moisture, adjusted according to your skin’s needs. For example, if you have dehydrated but oily skin, you should layer more humectant hydrating products and finish with a fairly light emollient moisturizer. If your skin is quite dry, heavier occlusives may need to come into play. Consider your skin condition, experiment with products, and find the balance that’s right for you.

Until next time,


Kay Beauty

  • Post author
    Kay Beauty

Comments on this post (2)

  • Sep 07, 2017

    Hi Marya!

    A richer cream that’s fortified with ceramides and oils would be great for the winter. I’d recommend the Cosrx Honey Ceramide Cream!


    — Kay Beauty

  • Jun 07, 2017


    What kind of moisturizer i can use in the winter time ? which will protect my skin from dryness .I moved in Sweden some months ago so the winter weather took by surprise my skin , it was a rought time !

    — Marya

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