For the sake of understanding the rest of the content of this post, let’s do a quick refresher on the anatomy of the skin, shall we? The skin has 3 layers, from superficial to deep, namely: epidermis, dermis and hypodermis. When we moisturize the skin, we target the epidermis, which itself is made up of 5 layers. The details are not too important, but just help with understanding better the rest of the post.

Microscopic cross section of the epidermal layers

The point of a moisturizer is to ensure that the skin remains a tight barrier by reducing what we call trans-epidermal water loss (TEWL)- basically, maintaining the water content of the epidermis. Contrary to popular belief, a moisturizer doesn’t really add moisture, it mainly prevents the skin from losing what moisture it already has. If you need a little recap on the functions of the skin, check out one of my earlier posts:

Although we all know more or less what a moisturizer is, it’s hard to find a universally accepted definition a moisturizer.  A moisturizer is made up of three main constituents- either alone, or more often, in combination with one another.

  1. Occlusives: these substances are meant to create a hydrophobic or water-resistant film over the skin.
Naturally occurringSynthetic
Sebum (from pores)Petrolatum (vaseline)
Vitamin ELanolin (a fatty acid)
SqualenePropylene glycol (an alcohol)

The most popular and widely used occlusive is petrolatum- the stuff we all got smeared on our faces as children- found in Vaseline. It is a brilliant occlusive. The downside to the occlusives is that some may find them greasy, and they are potential allergens for those with sensitive skin.

2. Emollients: these work by filling the gaps and cracks between the cells of the epidermis. There are 4 different categories of emollients, depending on the property. The details aren’t necessary for this post. Some examples include propylene glycol,  castor and jojoba oils.

3. Humectants: substances which attract water from the deeper dermis layer into the epidermis. In high humidity conditions, these may also be able to attract moisture from the external environment. There are many examples which you’ve probably noticed in your face and body products: glycerine, urea, hyaluronic acid, panthenol (pro-vitamin B5) and the alpha hydroxyl acids.

So, all that said, to make matters even more complicated, there are different types of formulations which are designed to deliver these ingredients. These are sometimes referred to as vehicles. These formulations differ on the target of the skin type as well the region of the body they’re used on. Simplified, it’s all about how “heavy” the formulation is, which is determined by the ratio of water to oils/waxes. From “lightest” to “heaviest:”


These have a liquid base. They are non-oily, easily absorbed, and are known to be non-comedogenic (less likely to clog up pores and cause acne.) They’re great for people with oily skins. An example is the Neutrogena Hydro Boost Water Gel.


These are a combination of oil, water and propylene glycol (an alcohol that acts as an occlusive and humectant). These are thin, easy to apply, and non-greasy. They are great for people with combination to dry skin. One that I personally use and love is the Clinique Dramatically Different Lotion.


These contain heavier fats and oils, at a ratio of 50/50 with water. In my opinion, this is one of the most balanced formulations- again, a good middle ground for those with combination skin. Even those with oily skin may benefit from creams in the dry winter months. Most body moisturizers are formulated as creams. I personally enjoy the Derma Hydrate Cream- it absorbs well, non-greasy and fragrance free.


The ratio of oils to water is closer to 80/20. These mainly contain water resistant ingredients and occlusives. They are great for those with very dry skin. Because of their occlusive nature, they should not be applied in hairy regions such as the armpit, because they have a tendency to clog and inflame hair follicles. The Eucerin Aquaphor Soothing Skin Balm is an ointment I enjoy applying on my lips. It applies like a vaseline, but so much more refined.

Let’s wrap it up. Theres so much more that could be said, but I want this post to be more of a reference post that you can keep coming back to as you try out different products. It’s important to note that depending on variables such as season, the health of your skin, hormonal status, the moisture requirements of your skin may change- so don’t feel compelled to stick to one product.

I will also be putting up an Instagram video on my page to chat through this post, just to clarify a lot of the scientific jargon.

In the meantime, enjoy building your moisture arsenal as we head into the dry winter (in most parts of South Africa, at least). Always read the ingredients of what you put on your skin- empower yourself as the consumer and end-user of a product.

Yours in a life well lived,


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