Perfectly hydrated skin? Not without understanding this crucial detail!
In the vast world of cosmetics, it is not enough to moisturize your skin every day. You also need to know how to do it. how We moisturize it. Because not all creams are created equal, and behind the word “moisturizer” actually refer to three types of ingredients with very distinct functions: humectantsthe emollients and occlusives. To keep skin supple, soft, and protected, it is crucial to understand their role, their synergy... and their limitations.
Three families of moisturizing agents: an essential division
Products labeled as «moisturizers» actually combine three complementary mechanisms:
- Humectants draw water into the skin
- Emollients fill cracks and soften
- Occlusives prevent water evaporation
1. Humectants: water magnets
Humectants are hygroscopic molecules capable of capturing moisture present in the air or in the deeper layers of the skin and bringing it to the surface. They thus help to increase the water content of the stratum corneum, the skin's first visible barrier.
Examples of humectants:
- Hyaluronic acid : naturally present in the skin, it retains up to 1,000 times its weight in water.
- Glycerine : widely used for its ability to relieve dry skin.
- Urea, PCA, lactic acid, fructose : also present in the skin's Natural Moisturizing Factor (NMF).
Caution: if the skin barrier is damaged, these humectants may have the opposite effect and increase dehydration.
2. Emollients: repair and soften the skin's surface
Emollients are lipids or fatty substances that insert themselves into the intercellular spaces of the stratum corneum. Their primary function is to soften the skin by partially replenishing the intercellular lipid cement.
Their role is not limited to “feeding”
Contrary to popular belief, emollients do more than just «nourish.» They improve the skin's barrier function, reduce water loss, and help maintain elasticity.
Examples of emollients:
- Ceramides : essential lipids naturally present in the skin.
- Vegetable oils : (argan, jojoba, coconut, sunflower, etc.) rich in fatty acids.
- Shea butter, squalane : restorative and well tolerated.
- Fatty alcohols : softeners.
3. Occlusives: the final barrier against evaporation
Occlusives do not penetrate the skin but form a protective layer on its surface. Their mission: prevent water from evaporating, a phenomenon known as transepidermal water loss (TEWL). Without an occlusive agent, the water provided by humectants evaporates quickly.
The most powerful water shields
- Lanolin, mineral or vegetable waxes : protect and strengthen the hydrolipidic film.
- Rich oils and butters Some emollients also act as mild occlusives.
Why do they need to be combined?
Using only a humectant, without emollients or occlusives, can further dry out fragile skin. Conversely, an occlusive without moisturizer does not provide water to the skin. It is therefore recommended to layer:
- A humectant (brings water)
- An emollient (repairs the lipid barrier)
- An occlusive (seals in moisture)
This multi-layered approach mimics the skin's natural function and maximizes the effectiveness of your routine.
Moisturizing or nourishing: they are not the same thing
- Hydrate = provide water (via humectants)
- Feeding = providing lipids (via emollients)
Dry skin lacks oil, dehydrated skin lacks water... but often, both deficiencies coexist. That's why a combined approach is essential.
