WTF are... humectants/emollients/occlusives anyway?
There are 50 ways to leave your lover and 3 ways to say "moisturiser"
So… WTF is it?
3 terms to describe different moisturising methods
How do you pronounce it?
Hew-meck-tant
Em-mole-ee-ent
Ock-loose-iv
What’s the point of it? I mean, what does it actually do?
Humectant - attracts water to the skin, promoting skin hydration
Emollient - This is what we traditionally thought of as ‘a moisturiser’. It seals cracks in the skin, strengthening the skin’s natural protective layer. Some humectants and occlusives are also emollients.
Occlusive - creates a physical barrier on the surface of the skin to protect it and seal moisture in the skin
NB This is the order in which they should be applied to the skin. Emollients and occlusives will be impenetrable to humectants if applied first. Apply your humectant(s) (if using), THEN your moisturiser to repair and lightly seal. Occlusives are for a thick layer, to keep everything under and not let anything else in.
Occlusives are typically used at night only, due to their thickness.
How does it work?
Humectants attract water from their surroundings and draw it into the epidermis. This moisturises the upper levels of the skin, plumping it out and reduces dryness, flakiness and cracking at the surface.
If there’s air has enough humidity, humectants will pull water vapour from it, but they can also draw it up from the dermis to the surface of the skin. This makes humectants highly effective in humid places but they can cause dry skin in drier climates.
Emollients restore oils into the skin. They often contain lipids or fatty substances that closely resemble those naturally found in the skin.
Their molecular structure integrates with and fills the gaps between skin cells, softening and smoothing the skin both in look and feel.
By filling those gaps, emollients form a flexible protective shield that maintains and reinforces the skin barrier, crucial for hydration/prevention of water loss and safeguarding the skin against external factors.
Humectants and emollients also promote cell turnover by loosening the bonds that attach dead skin cells to the skin1.
Occlusives usually2 have larger molecules than emollients, so they don’t integrate with the skin's matrix. Instead, they form a dense shield; a more distinct, physical layer on the skin's surface. This seals moisture in and prevents water loss through evaporation.
And why would someone want it?
All 3 can be used separately or in combinations, depending on your skin’s needs. If you’re treating any additional skin conditions (e.g. acne, eczema), this will affect the choices you make.
If you have oily skin, you may want to get most of your moisturisation from humectants, with a very light moisturiser to seal them in.
If you have dehydrated skin, you will need to find a balance between the 3 that works for your skin.
If you have dry skin, you should almost certainly be using an emollient daily and will likely benefit from an occlusive, on a frequent or occasional basis.
If you want to start slugging, this requires an occlusive.
How much is it?
All of these can be extremely cheap and extremely expensive.
The ingredients you’re looking for are:
Humectant - glycerin (v v cheap as an ingredient), hyaluronic acid3.
Emollient - shea/cocoa butter4, petrolatum, parrafin, lanolin, squalene, coconut/jojoba/sesame/rosehip/almond oils, mineral oil5
Occlusive - petrolatum, silicones (often Dimethicone), bee/carnuba wax, squalane, castor oil, shea butter
Where the same ingredient appears as both an emollient and an occlusive, if used as an emollient, it will be blended with other ingredients to shrink the molecular structure of the product and make it less dense. Check the formulation before buying something that can be both an emollient and an occlusive - even if you’ve used the ingredient in a different product - to make sure that it suits your skin.
Does it hurt?
No. The only risk is that you apply something that’s too heavy for your skin, which can feel uncomfortable or cause blocked pores.
Have I had it?
My life is a constant quest for the perfect moisturisation cocktail. I have oily skin that tends to dehydration and I also manage eczema and psoriasis.
Would I have it?
I don’t use all of these daily, but I currently have glycerin, hyaluronic acid, Dimethicone, paraffin, rosehip oil and (light) shea butter in my skincare rotation.
Should you have it?
You will need at least one of these on your face in some form or other.
Anything else I think you should know?
Check your existing products. Layering is important.
If you’re unwittingly layering an occlusive before a humectant, the humectant is rendered more or less useless. Similarly, an emollient should seal in a humectant to optimise moisturisation.
There is such a thing as a semi-occlusive, but I’m not getting into that here 😂6.
This is the best version of 50 Ways To Leave Your Lover. Don’t @ me.
Disclaimer: ‘WTF is…’ guides are intended to be a 3-5 minute introduction to a topic. They are, by their nature, not exhaustive.
If you have a concern that I’ve irresponsibly included/omitted information, don’t hesitate to get in touch to let me know and I’ll take a look.
Reminder that any cosmetic work undertaken should be in accordance with The 6 rules of cosmetic work. Here they are, in case you missed them the first time…
This is called desquamation #Science
There are other factors, such as stability and formulation, but this is a decent - if imperfect - rule of thumb.
There are others, but these are the big 2 and if you didn’t know what a humectant was until you started reading this, they’re all you really need to know for now.
If used as an emollient, butters will be blended with other ingredients to shrink the molecular structure of the product
“Wait… aren’t paraffin and mineral oil bad for me?” Nope. And thanks for playing ‘Tell Me You’re American Without Telling Me You’re American’. I will post on this at some point, but the amount of nonsense that gets pumped out of the US relating to ‘harmful’ skincare ingredients is astonishing. Whilst its residents are simultaneously chowing down on corn syrup and steroid-pumped meat. It’s mind-boggling, honestly.
La Roche Posay Cicaplast Baume is the best-known example.