Skin Care

what is a moisturiser

What is a moisturiser?

It interests me as an aesthetician that few textbooks in dermatology devote little space to this subject.

No standard definition really exists, yet we use and recommend moisturisers daily.

Technically, a moisturising treatment involves this 4-step process:

  • Repairing the skin barrier
  • Increasing water content
  • Reducing trans-epidermal moisture loss (TEWL)
  • Restoring the lipid barriers’ ability to attract, hold and redistribute water

I believe they are a vital part of the skincare routine regarding skin health.

So join me as I decode your moisturiser so you can appreciate how much of a role it plays in the health of your skin.

Benefits of a Moisturiser

  • they offer moisturising properties
  • an SPF moisturiser can prevent signs of photodamage
  • they can provide a soothing, calming relief
  • they provide an occlusive layer, keeping the skin soft and supple
  • when formulated with cosmecuticals, they can help to improve the appearance of ageing
  • antioxidant-rich moisturisers can prevent free radicals from causing oxidation
  • humectant rich moisturiser locks moisture against the skin, slowing evaporation and keeping it hydrated
  • balancing ingredients in a moisturiser can slow the flow of oil on the skin
  • a probiotic-rich moisturiser will replenish the delicate microflora and repair the acid mantle
  • moisturisers containing lightening and brightening ingredients, helping to pull deep-rooted pigmentation from within the skin’s tissues
  • ceramide-rich moisturisers can fill the cement-like substance between the cell walls to maintain the all-important protective barrier function

How do moisturisers work?

Traditionally, moisturisers were used to inhibit transepidermal water loss.

Water begins in the deep epidermal layers and moves up to hydrate cells in the stratum corneum, the outer layer of skin, eventually being lost to evaporation.

The occlusive moisturisation helps to prevent the dehydration of the stratum corneum.

Fortunately, much more is known about the function of moisturisers now and the skin layers.

Your skin has a Natural Moisturising Factor (NMF), which contains amino acids, lactates, urea, and electrolytes, which help the stratum corneum retain water.

Typically, dry skin occurs when the moisture content is less than 10%.

Components that make up your moisturiser

Several groups of substances are based on their theoretical mechanism of action.


Occlusives form a film over the skin’s surface, creating a protective barrier and preventing TEWL.

Follow the link to find out more about these essential ingredients.


Humectants attract water when applied to the skin and improve the hydration of the stratum corneum.

You must be careful with humectants because water drawn to the skin is trans-epidermal, not atmospheric moisture.

Continued evaporation from the skin can exacerbate dryness, so we suggest layering humectant-based products such as our H20 hydrating skin shot with an occlusive ingredient.

Our natural moisturising factor (NMF) is made up of a mix of these low molecular weight soluble hygroscopic ingredients, including glycerin, sorbitol, urea, amino acids, and sodium PCA.

The alpha-hydroxy acid lactic acid is a natural compound that is a major player in keeping skin hydrated and flexible.


The “bricks and mortar” model I discuss here suggests its role as an active membrane.

Loss of intercellular lipids, such as essential ceramides, cholesterol, and fatty acids, which form the bilayers of the skin, can damage the barrier function, causing a whole host of skin conditions.

Fortify barrier repair cream contains replenishing, skin-identical ingredients: glycerin, sorbitol, hyaluronic acid,  ceramides, cholesterol, and fatty acids.

This increases the cohesion of the stratum corneum cells, preparing the barrier function and maintaining the skin’s natural moisture function whilst reducing roughness and scaling, keeping skin soft, supple, plump and youthful.

Emollient Ingredients

These ingredients give a product that immediate feel of moisturisation.

Emollients improve skin texture by smoothing the skin and offering great slip.

They are essential in binding and desquamating corneocytes in the epidermis, filling the spaces between the skin flakes like mortar between bricks with oil droplets.

Combined with an emulsifier, they help hold oil and water in the stratum corneum.

Vitamin E is a common additive, as are cholesterol, squalene, jojoba, and structural lipids.

Stearic, linoleic, linolenic, oleic, and lauric are found in palm, coconut, and wool fat and are long-chain saturated fatty acids and fatty alcohols.

These change the properties of intracellular lipids in the stratum corneum. They are used in topical cosmetic formulations, where they exert their benefits through effects on the skin barrier and permeability.

Essential fatty acids, such as linoleic and alpha-linoleic acids, influence skin physiology via their beneficial effects on skin barrier functions, membrane fluidity, and cell signalling.

Structural lipids are intracellular lipids located between stratum corneum cells; they play a significant role in the skin’s water-holding capacity. Ceramides are a substantial component of the inner cellular lipids and are vital in maintaining skin health and improving dry skin conditions.

Do Moisturisers that Contain Collagen Work?

Collagen and other proteins, including keratin and elastin, claim to rejuvenate the skin by replenishing essential proteins.

However, this is unlikely to occur because these protein molecules are too large to penetrate the epidermis, your outer layer of skin.

Instead, they provide a temporary protein film that smooths the skin when applied topically.

AHA’s in Moisturisers

Alpha hydroxy acids like glycolic and lactic acids absorb deep within the skin tissues. Because of their small molecular structure, they can dissolve surface cells that adhere to the skin’s surface, making it smooth and more hydrated.

To Conclude. The naked truth

As you can see, the different classes of moisturisers and their roles on your skin are based on their action.

Some are occlusive, whilst others are hydrating, emollient, or rejuvenation.

When considering skin health, having a fundamental understanding of the physiochemical effects of moisturisers and how they interact with the skin and barrier function gives us an added advantage as formulators on how best to develop physiologically effective products to prevent and treat skin types and their related skin conditions.

To that end, we believe we are in a powerful position to help people get accurate results with their skin through the topical application of intelligently formulated products.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.