What’s the skin barrier?  We demystify the Stratum Corneum and highlight the science behind it and the secret to naturally radiant skin

At SINHA we are obsessed with the skin barrier.  I didn’t fully appreciate how important the skin is until I started studying cosmetic sciences.  Honestly, the basics of our skin barrier should be taught to us is in high school alongside biology!

What is skin?

We all know the skin is the outer covering of our body, but it’s also the largest organ we have.   Think of the other organs that you have – heart, kidney or liver.   A failure of any of these would be life threatening and the same goes for our skin, which quite honestly, we all treat like a rubber tyre.  

What does the skin do?

The skin has multiple functions and some of the most important are these:

Temperature regulation:  excessive heat causes us to (e.g.) sweat and excessive cold causes us to shiver

Sensation:  our skin houses the nervous system (e.g.) we feel heat, pain & pleasure through the skin

Cushioning:  if you have a sibling then you’ve had the good fortune of being thumped at least once during your childhood.  The skin (or at least the fat layer) cushions the blow

Protection against UV damage:  darker skin has the skin pigment melanin, which I like to think of as our internal SPF, because it protects the skin from damage caused by excessive exposure to UV radiation.

Physical barrier:  lastly but not least the most important function of the skin is to act as a physical waterproof barrier separating our body from the external environment.  Depending on what type of cell you are referring to, the percentage component of water is very high.  We would become desiccated coconuts were it not for our skin

Why is the skin barrier matter for “beauty”?

Without any support, our skin slowly starts to appear less youthful, radiant and becomes dull, uneven toned, pigmented and less firm.   It’s unsurprising that since the age of Cleopatra to now (multi-billion-dollar cosmetic industry) we have always wanted to look more youthful. 

However, from a cosmetic science perspective, the most important function of any skincare product is to respect your skin barrier, support and restore it.  

Why?  Because a healthy barrier is automatically calmer, smoother and more naturally radiant

What is the skin barrier?

The skin has 3 main layers: the epidermis, dermis and the hypodermis (subcutaneous fat layer).   

When researchers, beauty editors, instabloggers etc etc. talk about the SKIN BARRIER, they mean STRATUM CORNEUM.

The Stratum Corneum is the outermost layer of the skin and is also the part of the epidermis that is visible to the eye. 

What does the stratum corneum look like?

Historically it’s been described as a brick and mortar model, composed of interlocking pentagonal corneocytes (bricks) enmeshed in a lamellar lipid matrix (mortar).

If you take away anything from this blog its this: that the stratum corneum or the skin barrier is made of:

• PROTEIN (keratin – the corneocytes) which provide structure
• intercellular LIPID matrix which holds the bricks together.  The matrix contains amongst other things, lipids that are ceramides, cholesterol and fatty acids.

The stratum corneum is the principal barrier in the skin that prevents water loss and protects the skin from UV light, oxidants, antigens and toxic agents.