Understanding Moisturizers

Moisturizers are extremely important for maintaining skin health. They restore the skin’s own barrier function, provide a protective film against the elements, and increase the water content of the epidermis, leading to improved skin texture and appearance in the short term, and more youthful-looking skin in the long term.

Moisturizers come in a variety of forms; they include mists, serums, gels, oils, balms, butters, lotions, creams, ointments, and gels. Because there are so many types of moisturizing products on the market, it can be hard to understand the specific function of each, or how they should be used and combined to create the best daily skincare routine for you. But, as overwhelming as the world of skincare can be, understanding the individual ingredients in moisturizers and what they do can make it a lot less confusing.

Moisturizing formulas always include one or multiple of the following types of ingredients: emollients, humectants, and occlusives. While they have separate functions, they often work together to maintain proper moisture levels in the skin. We’ll dive into each one in depth below.

THE THREE TYPES OF MOISTURIZERS

EMOLLIENTS

Emollients are the ingredients you most often think of when you think of moisturizers. In fact, the two words are often used interchangeably even though they mean different things. Emollients consist mainly of lipids and oils. They soften, soothe, and nourish the skin to improve its texture, appearance, and barrier function. Here are a few different examples of common emollients:

• Plant oils and butters, e.g., coconut oil, olive oil, avocado oil, and shea butter

• Oils derived from animals, e.g., lanolin and emu oil

• Fatty alcohols (not to be confused with simple or solvent alcohols), e.g., cetyl alcohol and stearyl alcohol

• Silicones, e.g., dimethicone and cyclomethicone

• Squalene

Alone, emollients aren’t as effective as when used together with humectants, and in certain cases occlusives too. Think of emollients as oil with no water - both are necessary for proper skincare. If you prefer to moisturize with oils, this is why we recommend applying the oils to damp skin after a shower, or using a mist containing humectants as a first layer.

HUMECTANTS

If emollient oils are the first thing you think of when you hear “moisturizing,” then think of humectants as “hydrating.” Humectants are hygroscopic compounds that attract water from their surroundings. When applied to the skin, this means they can draw water from the dermis (the deeper second layer of skin) into the epidermis (the upper visible layer). In humid surroundings, they will also draw moisture from the environment into the skin, to a degree. Some common humectants are as follows:

• Glycerin

• Honey

• Aloe vera

• Hyaluronic acid

• Alpha hydroxy acids, e.g., lactic acid, glycolic acid

• Propylene glycol and butylene glycol

• Urea

Humectants are, however, a double-edged sword. By pulling moisture up from deeper layers of the skin and onto the surface, where it can more easily escape into the air, they can actually contribute to greater transepidermal water loss. This is especially the case in dry conditions. For this reason, humectants are best when combined with occlusives.

OCCLUSIVES

Occlusives are heavier, often waxy substances that form a water-resistant, physical barrier over your skin to lock in moisture. They’re critical in drier climates, which can suck moisture out of the skin. it’s helpful to know that some emollient oils, particularly those high in oleic acid, also have occlusive properties. Some common examples of occlusives are:

• Vegetable waxes, eg., candelilla and carnauba

• Wax esters, e.g., beeswax and lanolin

• Petroleum derivatives, e.g., petrolatum and mineral oil

The downside is that occlusives can have a greasier, thicker feel, so they’re best when included with lighter ingredients or used in smaller amounts. They can also seal in contaminants if applied to unclean skin, which is why proper cleansing before moisturizing is always crucial.

DECODING MOISTURIZERS

The best moisturizers or moisturizing routines combine all three of these ingredient types to provide comprehensive protection against skin dehydration. Here are some of the common forms of moisturizers and how they fit into the bigger picture:

• Mists, serums, and gels are generally water-based formulas. This is where you should look for some high-quality humectants in the ingredients list, as humectants are almost always water-soluble.

• Oils, butters, and balms are great as emollient products, and they can have some occlusive benefits as well, especially balms which often contain waxes for hardening.

• Lotions and creams combine both oil and water, with the potential to offer humectant, emollient, and occlusive ingredients all in one product. The trade-off is that they often contain more synthetic or processed ingredients, since they require emulsifiers and preservatives (a topic for a future post). Humectants can be incorporated into the water portion of lotions and creams, and emollients and occlusives can be incorporated into the oil portion. Creams are heavier than lotions and tend to be more occlusive.

• Finally, ointments are oil-based and may or may not also contain water, but only a small amount. They are heavily occlusive and are often used to completely seal off skin for intensive healing and protection. They are often greasy and heavy due to their occlusive nature.

At Oil + Water, we use only natural and plant-based versions of the ingredients discussed above, because there are so many wonderful natural options available to us. We formulate our Face Mist with calendula-infused glycerin, a tough-to-beat gentle and natural humectant. And our Face + Hair Oil contains a touch of cupuaçu butter, which, in addition to being a fantastic emollient, is also a powerful natural occlusive agent. We recommend using the two products in tandem (mist, then oil immediately afterwards) for the best results.

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Kraft, John, and Charles Lynde. “Moisturizers: What They Are and a Practical Approach to Product Selection.” Skin Therapy Letter, vol. 10, no. 5, 2005, pp.1–8.

Sethi, Anisha et al. “Moisturizers: The Slippery Road.” Indian Journal of Dermatology, vol. 61, no. 3, 2016, pp: 279-87. doi:10.4103/0019-5154.182427