How plant oils strengthen the skin barrier – Part one

How plant oils strengthen the skin barrier. Photo by July Prokopiv
How plant oils strengthen the skin barrier. Photo by July Prokopiv


The skin barrier has such an important role in maintaining happy and healthy skin but how can we care for it for optimum strength? In this two part series we’ll be exploring both aspects, with a particular focus on our favourite ingredients – plant oils…



The skin has three main layers – the epidermis, dermis and hypodermis. The skin barrier is the outermost layer of the epidermis, also known as the stratum corneum. This barrier (which is approximately 0.01mm thick) protects the skin from UV rays/light, infection and irritants such as environmental toxins, as well as preventing the skin’s natural moisture from escaping.

Here comes the science bit – the stratum corneum (the outermost layer or skin barrier) has a ‘brick and mortar’ type structure. The ‘bricks’ are called corneocytes which form a tough, insoluble protein barrier – a major structural component of the outer layers of skin. There are about 12 to 16 layers of corneocytes in the stratum corneum resulting in different skin thicknesses across the face and body (for example, the skin under the eyes is much thinner and more delicate as it has fewer layers of corneocytes). The ‘mortar’ refers to the corneocytes being cemented together by ceramides which are made up of lipids and sebum. The ceramides keep skin supple and strengthen the skin barrier by allowing the dead skin cells to be turned over and sweat/excess sebum to be removed through pores but not letting anything else leave/enter. This outermost layer provides protection to the normal function of cell regeneration which takes place beneath it. We will cover healthy cell regeneration in another post.


You might also like to read: The Skin Microbiome – What Is It And How To Support It



Small, invisible cracks are created when the protective barrier gets damaged. The corneocytes are weakened and ceramide production declines, meaning moisture can escape and irritants can enter more easily. This results in tight, dehydrated, inflamed, irritated, sensitive skin and conditions such as dermatitis, rosacea and eczema.

There are a number of ways this can occur such as:

  • Using products with alcohols in – alcohols such as ethanol, isopropyl alcohol, ethyl alcohol, SD alcohol 40 and alcohol denat are used to help retinol and vitamin C to penetrate the skin more easily, make thick products feel weightless and are sometimes used as preservatives. Although some serve a purpose in skincare such as reducing excess sebum, over time these harsh ingredients strip the skin of natural oils, weaken the skin’s barrier (which makes it more difficult to retain moisture and elasticity) and can even stop cell regeneration altogether.
  • Using products with synthetic fragrances (parfum) in – putting fragrance on the packaging doesn’t really give consumers any indication as to what they are actually applying to their skin. Made up of hundreds of chemicals, synthetic fragrances can cause reactions, dry out the skin and are commonly stabilised with phthalates which are linked to reproductive problems.
  • Using products with parabens (preservatives) in – despite them preventing the product from spoiling, parabens (usually identified by methyl, butyl, ethyl or propyl in the name) contribute to hormone imbalance which impacts the skin’s elasticity, collagen production, radiance, pH and hydration. They also behave like Oestrogen which can stimulate breast cancer cells to grow.


You might also like to read: Could Your Dry Skin Be Caused By Hormonal Changes?


  • Using products with mineral oils in – designed to provide the skin with moisture, these odourless ingredients such as propylene glycol, paraffin, butylene glycol, isopropyl alcohol and petrolatum (petroleum) can clog pores, thus there being a build up of sebum and sweat which mixes with bacteria leading to breakouts and other inflammation/irritation.
  • Using products with SLS in – sodium lauryl sulfate is a foaming agent which strips the skin of natural oils. As a result, the body produces even more of this and the corneocytes begin to swell. This changes the structure, alters pH, increases transepidermal water loss and compromises the barrier.
  • Using topical products prescribed for skin conditions – these can also increase the physiological process of transepidermal water loss making the skin drier. Topical steroids can also make the skin’s barrier thinner and more susceptible.
  • Over-exfoliating – exfoliating too abrasively or too frequently can cause micro tears in the skin’s barrier. The skin also becomes dehydrated as the ceramides are removed.
  • Sun damage, weather, hot water and air conditioning – the barrier may be designed to protect against UV rays and environmental toxins, but repeated exposure will again weaken the barrier.
  • Lifestyle factors: alcohol, smoking, poor nutrition – as with everything, we need to consider what we are putting in our bodies in order to aid our internal processes. Toxins and an unbalanced diet ultimately contribute to an ineffective skin barrier.
  • Genetics and natural aging – this may be out of our control but these factors are increased by all of the above.



Plant based oils are fats taken from plants, usually from their seeds. These are rich in nutrients such as essential fatty acids (EFAs), vitamins and antioxidants to strengthen the skin’s protective barrier, improve elasticity and slow down aging which has been accelerated by the factors listed above. The lipids (ceramides) which hold the barrier together naturally decrease as we get older, so using plant oils will help to replenish these, resulting in happy skin. We’re big fans of them because plant oils absorb easily and penetrate deep below the skin’s barrier to provide skin nutrition for cell regeneration. They also seal in the moisture and prevent the hyaluronic acid we naturally produce from evaporating. Combined with the natural oils, plant oils will draw out impurities and find the balance your skin needs to thrive.

In part two of this post we’ll be diving in deeper into how plant oils work and which to look for in your skincare products to promote a healthy skin barrier.


You might also like to read: Marula Seed Oil – A Miracle Oil



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