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What is the Skin Barrier?

Understanding the skin barrier, how it works and how to protect it

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What is the Skin Barrier?
Written byPippa HarmanCo-Founder Renude
Start your 2 minute skin quiz today and one of our aestheticians will create a personalised skincare routine for you!Take the skin quiz

With skincare becoming so popular over the years, we’ve seen an increase in customers who have damaged their skin barrier through trialling products that aren't suitable or try too many in one go. Getting a little over excited with a chemical exfoliant (or two!), or attempting an at-home peel can lead to irritation, burning, breakouts and dryness amongst other symptoms damaging your skin ‘shield’ aka skin barrier Often customers will try and ‘fix’ these symptoms with yet more products which, in many cases, can irritate the skin further.  We find that a number of our members come to us with their skin concerns without understanding their skin barrier has been impaired. 

That is where we come in. Thankfully a compromised skin barrier is possible to fix - you just need to make sure you’re using the right products and ingredients for your inflamed skin.. We aim to break down the science behind this essential layer of your skin and explain why it's crucial for maintaining healthy, radiant skin. 

What is the Skin Barrier?

Picture your skin as a protective shield, covering your entire body. The core of this defence system is the skin barrier, also known as the stratum corneum. It's the outermost layer of your skin, acting as a shield against harmful environmental factors such as pollution, UV radiation, and bacteria.

The skin barrier has the overall function to protect the body from external factors and is made up of several components that work together. In order of layers, from surface level to deeper into the skin, the components are made up of: 

The Microbiome: Also known as the microflora or microbiota, is the collection of microorganisms that live on and within your skin, including bacteria, fungi and viruses.

Acid Mantle: A thin, protective layer formed by the combination of sebum and sweat that helps to maintain the health and function of the skin barrier. This also gives skin its naturally acidic pH of around 5.5.

Lipid Layer: A thin layer of lipids (fats) primarily composed of ceramides, cholesterol, and fatty acids, that helps to prevent water loss from skin, as well as protects against harmful substances and infections.

We then reach the epidermis, the next layer of the skin, and below this, the dermis. 

You can already see how a carefully selected skincare routine can have an impact on this perfectly balanced and active environment - and also how easily it could disrupt the equilibrium!

How does the Skin Barrier Function?

The skin barrier's job is multifaceted, relying on several important functions to keep your skin happy and healthy:

  1. Moisture Retention: The skin barrier acts as a moisture barrier, preventing excessive water loss from the skin. It does this by producing natural moisturising factors (NMFs) while simultaneously creating a lipid seal between skin cells, which help maintain optimal hydration levels. This keeps your skin plump and supple, reducing the appearance of fine lines and dryness.
  2. Protection from External Aggressors: The skin barrier provides a physical barrier against environmental aggressors like pollutants, allergens, and harmful microorganisms. It prevents these invaders from penetrating the skin, reducing the risk of irritation, inflammation, and infection.
  3. pH Regulation: The skin has an optimal acidic pH that helps inhibit the growth of harmful bacteria and fungi. The skin barrier helps maintain this delicate balance, acting as a defence mechanism against potential microbial overgrowth.
  4. Defence against UV Radiation: The skin barrier also plays a role in shielding your skin from harmful ultraviolet (UV) radiation. While it's not a substitute for sunscreen, it contributes to the skin's natural protection against UV-induced damage.

How to Look After the Skin Barrier:

Now that we understand how vital the skin barrier is, let's explore some practical ways to keep it strong and resilient:

  1. Gentle Cleansing: Avoid harsh cleansers that strip away the skin's natural oils, as they can compromise the skin barrier. Opt for mild, pH-balanced cleansers that effectively remove impurities without disrupting the delicate balance of your skin.

Renude Recommends: CeraVe Hydrating Cleanser, Harborist Gel Balm Cleanser

  1. Hydration is Key: Hydrating your skin is essential for supporting the skin barrier. Look for moisturisers which are both rich in humectants like hyaluronic acid and glycerin, which draw and lock in moisture, lipids like ceramides and cholesterol, and occlusive oils to create a protective seal, preventing water loss.

Renude Recommends: Eucerin Urea 5%, Medik8 Advanced night restore

  1. Sun Protection: While the skin barrier offers some defence against UV radiation, it's crucial to supplement it with broad-spectrum sunscreen. Shield your skin from harmful rays by using a sunscreen with a high SPF and UVA/UVB protection.

Renude Recommends: Heliocare Water Gel SPF50, Thank You Farmer Sun Light Essence SPF50

  1. Avoid Over-Exfoliation: Exfoliation can be beneficial for your skin, but overdoing it can damage the skin barrier. Opt for gentle exfoliants and limit their use to a few times per week to avoid excessive irritation or inflammation.

Renude Recommends: GoW PHA Serum, Medik8 Press & Clear

How to Tell if the Skin Barrier is Impaired:

Sometimes, despite our best efforts, the skin barrier may become compromised. Here are a few signs that indicate your skin barrier might need some extra TLC:

  1. Dryness and Flakiness: A weakened skin barrier often leads to increased water loss, resulting in dry, flaky skin. If your skin feels rough, looks dull, or experiences excessive peeling, it may be a sign of an impaired barrier.
  2. Sensitivity and Irritation: When the skin barrier is compromised, it becomes more susceptible to external irritants. If you notice increased redness, itching, or stinging after using skincare products, your skin barrier might need attention.
  3. Breakouts and Inflammation: A weakened skin barrier can disrupt the skin's natural defence against bacteria and other microbes, leading to increased breakouts, or a flare up of inflammatory skin conditions like acne, eczema or rosacea.

What to Do if the Skin Barrier is Impaired:

If you suspect that your skin barrier is impaired, there are steps our aesthetician recommend you can take to help repair and strengthen it:

  1. Simplify Your Routine: Simplify your skincare routine by eliminating harsh or unnecessary products. Stick to gentle cleansers, hydrating moisturisers, and minimalistic formulations that promote barrier repair.
  2. Introduce Barrier-Repairing Ingredients: Look for skincare products formulated with barrier-repairing ingredients such as ceramides, niacinamide, and fatty acids. These ingredients can help restore and fortify the skin barrier.
  3. Avoid Irritants: Minimise exposure to potential irritants such as fragrances, alcohol, and harsh exfoliants. These can further aggravate the skin and impede barrier repair.
  4. Seek Professional Advice: If your skin barrier concerns persist or worsen, a Renude aesthetician can help. They can provide personalised guidance and recommend targeted treatments to address your specific needs.

When we take care of our skin we promote a healthy, resilient barrier that will protect from pollutants and sun damage, keeping skin glowing and youthful for longer!

If you have specific skin concerns, please consult a Renude aesthetician for advice, take our simple skin quiz to get started! 


Skin Barrier Function and the Microbiome - PubMed (

The Difference Between the Skin Microbiome And Skin Barrier (

Why Your Skin Barrier Matters and How to Repair Damage in 2023 (

Microbiota and maintenance of skin barrier function | Science

Pippa HarmanCo-Founder Renude
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Pippa HarmanCo-Founder Renude
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