The skin lipid barrier is a key element in the health and protection of our skin. This natural barrier, composed of lipids, plays an essential role in maintaining hydration and protection against external aggressions. Understanding how it works and knowing how to preserve it is crucial to maintaining healthy skin, whether it is dry, oily, or combination.
The skin lipid barrier: what is it?
The skin lipid barrier is located at the level of the stratum corneum , the outermost layer of the epidermis. It is made up of lipids, mainly fatty acids , cholesterol, and ceramides, which form a kind of "cement" between the skin cells. This barrier is covered by the hydrolipidic film , a thin layer on the surface of the skin composed of an oily phase (sebum produced by the sebaceous glands) and an aqueous phase (sweat).
What is the role of the lipid barrier?
The lipid barrier has several essential functions for skin health:
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Protection against external aggressions : It acts as a physical and chemical barrier against external aggressions such as pollution, UV rays, climate changes, and chemical irritants. It also prevents the penetration of potentially pathogenic microorganisms, helping to maintain healthy skin.
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Hydration maintenance : The lipid barrier limits transepidermal water loss (TEWL), i.e. the loss of water through the epidermis to the external environment. By retaining water inside the skin, it helps maintain its hydration and suppleness.
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Skin pH regulation : The hydrolipidic film helps maintain an acidic pH on the skin surface, between 4.5 and 5.5. This slightly acidic pH protects the skin against the proliferation of harmful microorganisms.
Why is the lipid barrier important?
When the lipid barrier is intact, the skin is well hydrated, supple, and less prone to irritation. On the other hand, if this barrier is compromised, the skin becomes vulnerable to external aggressions, which can lead to various skin problems:
- Dry Skin : A damaged lipid barrier can cause excessive water loss, leading to dry, rough, and flaky skin.
- Oily skin : Sometimes skin that appears oily is actually dehydrated; the skin then produces more oil to compensate for the water loss.
- Irritations and sensitivities : A weakened barrier allows irritants and allergens to pass through more easily, leading to redness, itching, and inflammation.
How to take care of the lipid barrier?
A proper beauty routine is essential to protect and restore the lipid barrier. Here are some tips to take care of it:
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Use a gentle cleanser (morning and evening) : Choose a gentle, sulfate-free cleanser that does not disrupt the skin's natural hydrolipidic film . A cleanser that is too aggressive can remove protective lipids, altering the skin barrier.
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Moisturize your skin : Apply a moisturizer that is appropriate for your skin type . For dry skin, choose creams rich in fatty acids, ceramides, and cholesterol, which strengthen the lipid barrier. For oily skin, opt for a light cream that moisturizes without clogging pores. Hyaluronic acid , a powerful hydrating agent, can also be used to retain water in the skin.
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Maintain a pH balance : Use skincare products that respect the skin's acidic pH to avoid disrupting the skin barrier. Products with a neutral or slightly acidic pH are ideal for preserving the hydrolipidic film.
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Adapt your beauty routine according to your skin type : Dry skin will benefit from richer and more nourishing care to compensate for the lack of lipids. Oily skin should favor non-comedogenic products that do not weigh down the skin but help maintain lipid balance.
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Avoid aggressions : Limit exposure to factors that can damage the skin barrier, such as hot water, intense cold, and products containing alcohol or irritating ingredients.
What ingredients should you use to strengthen your skin barrier?
Strengthening the skin barrier is essential to maintaining healthy, hydrated skin that is protected from external aggressions. Certain ingredients, when incorporated into your skincare routine, can help restore and strengthen this natural barrier. Here are the main ingredients to focus on to support the skin barrier:
1. Ceramides
Ceramides are lipids naturally present in the skin that play a key role in the structure and function of the skin barrier. They act as a “cement” between skin cells, helping to retain water and protect against external aggressions. Using products containing ceramides can help replenish the skin’s natural levels, improving its hydration and resilience.
- Product example : Moisturizers or serums enriched with ceramides.
2. Essential fatty acids
Essential fatty acids such as linoleic acid (omega-6) and alpha-linolenic acid (omega-3) are vital for maintaining the suppleness and integrity of the skin barrier. They help reduce transepidermal water loss and improve barrier function. Vegetable oils such as argan, borage, jojoba, and hemp are rich in essential fatty acids.
- Product example : Pure vegetable oils or moisturizers containing oils rich in essential fatty acids.
3. Cholesterol
Cholesterol is another major lipid component of the skin barrier. It helps maintain cohesion between skin cells and prevent moisture loss. Skin care products containing cholesterol can help restore barrier function, especially for dry or damaged skin.
- Product example : Repairing and emollient creams with cholesterol.
4. Hyaluronic acid
Hyaluronic acid is a powerful moisturizer that can hold up to 1000 times its weight in water. It helps to deeply hydrate the skin and improve its elasticity. Used in serums and moisturizers, it helps strengthen the skin barrier by maintaining optimal hydration levels.
- Product example : Hyaluronic acid serums or moisturizers.
5. Niacinamide (Vitamin B3)
Niacinamide is a multifunctional ingredient that helps strengthen the skin barrier by stimulating the production of ceramides and fatty acids. It also has anti-inflammatory properties that can reduce redness and irritation, while improving skin hydration and texture.
- Product example : Serums and creams containing niacinamide (usually between 2% and 5%).
6. Panthenol (Provitamin B5)
Panthenol is known for its moisturizing and soothing properties. It helps strengthen the skin barrier by attracting and retaining moisture in the skin, while helping to repair and protect against irritation.
- Product example : Repair balms, moisturizers and masks containing panthenol.
7. Allantoin
Allantoin is a soothing ingredient that promotes skin regeneration, reducing irritation and redness. It also helps improve the skin's barrier function, keeping it soft and hydrated.
- Product example : Creams and lotions for sensitive skin containing allantoin.
8. Glycerin
Glycerin is an effective humectant that attracts water into the skin, helping to maintain optimal hydration levels. It also helps strengthen the skin barrier by reducing transepidermal water loss.
- Product Example : Moisturizers, body lotions, and mild cleansers containing glycerin.
9. Soothing plant extracts
Plant extracts like aloe vera , chamomile , and green tea have anti-inflammatory and soothing properties that can calm irritation and support the skin's barrier function. These ingredients are especially beneficial for sensitive or reactive skin.
- Product example : Soothing serums, moisturizers and masks containing plant extracts.
10. Colloidal Oat Milk
Colloidal oatmeal is known for its moisturizing, soothing and anti-inflammatory properties. It helps protect the skin barrier against irritation and external aggressions, while restoring the skin's moisture balance.
- Product Example : Moisturizers, gentle cleansers, and colloidal oatmeal masks.
Conclusion
The skin's lipid barrier is essential for protecting the skin from external aggressions, maintaining its hydration, and preserving its balance. To maintain healthy skin, it is important to adopt a gentle skincare routine adapted to your skin type, using gentle cleansers, appropriate moisturizers, and avoiding irritants that can weaken this protective barrier. By taking care of the lipid barrier, we help maintain soft, supple skin that is resistant to daily aggressions.